{"id":2750,"date":"2023-10-03T12:52:18","date_gmt":"2023-10-03T12:52:18","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=2750"},"modified":"2023-10-03T13:13:44","modified_gmt":"2023-10-03T13:13:44","slug":"all-weeks-ss2-first-term-data-processing-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/all-weeks-ss2-first-term-data-processing-notes\/","title":{"rendered":"All Weeks &#8211; SS2  First Term Data Processing Notes"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS21.png\" alt=\"\"\/><br \/>\n\t<strong>DATA PROCESSING<\/strong><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS22.png\" alt=\"\"\/>FIRST TERM SCHEME OF WORK FOR SS TWO  <\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td><strong>weeks<\/strong><\/td>\n<td><strong>Content <\/strong><\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>REVISION <\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>DATA MODELS<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>DATA MODELING \u2013TYPES OF MODELS<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>DATA MODELING- CREATING TABLES,FORM,QUERIES AND REPORTS (PRACTICAL)<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>DATA MODELING-SIGNIFICANCE OF DATA MODEL<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td>DATA MODELING\u2013EXAMPLES OF STANDARD MODELS<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td>NORMAL FORMS \u2013NORMALIZATION AND CLASSES<\/td>\n<\/tr>\n<tr>\n<td>8<\/td>\n<td>NORMAL FORMS \u2013 CONCEPT OF PRIMARY AND FOREIGN KEY<\/td>\n<\/tr>\n<tr>\n<td>9<\/td>\n<td>NORMAL FORMS \u2013 DETERMINANTS<\/td>\n<\/tr>\n<tr>\n<td>10<\/td>\n<td>ENTITY RELATIONSHIP MODELS<\/td>\n<\/tr>\n<tr>\n<td>11<\/td>\n<td>REVISION <\/td>\n<\/tr>\n<tr>\n<td>12<\/td>\n<td>EXAMINATION <\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS23.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS24.png\" alt=\"\"\/><br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS25.png\" alt=\"\"\/><\/p>\n<h2>Definition<br \/>\n\t\t<\/h2>\n<p>\uf097\uf020A data model is a conceptual representation of the data structures that are required by a database. The data structures include the data objects, the associations between data objects, and the rules which govern operations on the objects. As the name implies, the data model focuses on what data is required and how it should be organized rather than what operations will be performed on the data. To use a common analogy, the data model is equivalent to an architect&#8217;s building plans.<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS26.png\" alt=\"\"\/><\/p>\n<h2>Concept of Data Modeling<br \/>\n\t\t<\/h2>\n<ul>\n<li>The concept of data modeling can be better understood if we compare the development cycle of a data model to the construction of a house. For example Company ABC is planning to build a guest house (database) and it calls the building architect (data modeler) and projects its building requirements (business requirements). Building architect (data modeler) develops the plan (data model) and gives it to company ABC. Finally company ABC calls civil engineers (DBA) to construct the guest house (database).\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS27.png\" alt=\"\"\/><\/p>\n<ul>\n<li>Data Engineers, Data Modeler and Data Architect are the common titles for those who are involved in data modeling. To become an efficient data modeler, you should have an overview about the database objects, constraints, normalization and understanding the requirements correctly.\n\t\t<\/li>\n<li>A data model can be thought of as a diagram or flowchat that illustrates the relationships between data.\n\t\t<\/li>\n<li>Data modelers often use different approaches to data modeling: it includes: Conceptual Data Modeling: identifies the highest-level relationships between different entities.  Enterprise Data Modeling : similar to condeptual data modeling,but addresses the unique requirements of a specific business.  Logical Data Modeling :- illustrates the specific entoities ,attributes and relationships involved in a business function.serves as the basis for the creation of the physical data model.   Physical Data Modeling :- represents an application and database-specific implementation of a logical data model.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS28.png\" alt=\"\"\/><\/p>\n<ul>\n<li>Database design is defined as: &#8220;design the\n\t\t<\/li>\n<li>logical and physical structure of one or more\n\t\t<\/li>\n<li>databases to accommodate the information\n\t\t<\/li>\n<li>needs of the users in an organization for a \uf097\uf020defined set of applications&#8221;. The design process \uf097\uf020roughly follows five steps:\n\t\t<\/li>\n<li>1. planning and analysis\n\t\t<\/li>\n<li>2. conceptual design\n\t\t<\/li>\n<li>3. logical design\n\t\t<\/li>\n<li>4. physical design\n\t\t<\/li>\n<li>5. implementation\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS29.png\" alt=\"\"\/>Components of A Data Model<\/p>\n<ul>\n<li>An entity-relationship diagram which represents the data structures in a pictorial form. Because the diagram is easily learned, it is valuable tool to communicate the model to the end-user. The second component is a data document. This a document that describes in detail the data objects, relationships, and rules required bythe database. The dictionary provides the detail required by the database developer to construct the physical database.\n\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS210.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS211.png\" alt=\"\"\/><br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS212.png\" alt=\"\"\/><\/p>\n<h2>Conceptual Data Model<br \/>\n<\/h2>\n<ul>\n<li>A <em>conceptual data model<\/em> is a summary-level data model that is most often used on strategic data projects. It typically describes an entire enterprise. Due to its highly abstract nature, it may be referred to as a <em>conceptual model<\/em>.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS213.png\" alt=\"\"\/>Common characteristics of a conceptual data model:<\/p>\n<ul>\n<li>Enterprise-wide coverage of the business concepts. Think <em>Customer<\/em>, <em>Product<\/em>, <em>Store<\/em>, <em>Location<\/em>, <em>Asset.<\/em>\n\t\t<\/li>\n<li>Designed and developed primarily for a business audience \uf097\uf020Entities will have definitions.\n\t\t<\/li>\n<li>\n<div>Designed and developed to be independent of DBMS, data storage locations or technologies. In fact, it would address digital and non-digital concepts. This means it would model paper records and artifacts as well as database artifacts.\n\t\t\t<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS214.png\" alt=\"\"\/><\/p>\n<h2>Logical Data Model<br \/>\n<\/h2>\n<ul>\n<li>A <em>logical data model<\/em> is a fully-attributed data model that is independent of DBMS, technology, data storage or organizational constraints. It typically describes data requirements from the business point of view.\n\t\t\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS215.png\" alt=\"\"\/><\/p>\n<ul>\n<li>Typically describes data requirements for a single project or major subject area.\n\t\t\t\t<\/li>\n<li>Contains relationships between entities that address\n\t\t\t\t<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u2022Entities and attributes will have definitions.cardinality and nullability (optionality) of the<br \/>\n\trelationships.<\/p>\n<ul>\n<li>Designed and developed to be independent of DBMS, data storage locations or technologies. In fact, it may address digital and non-digital concepts.\n\t\t<\/li>\n<li>Entities and attributes will have definitions.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS216.png\" alt=\"\"\/><br \/>\n\tA logical data model will normally be derived from and or linked back to objects in a conceptual data model.<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS217.png\" alt=\"\"\/><\/p>\n<h2>Physical Data Model<br \/>\n<\/h2>\n<ul>\n<li>A <em>physical data model<\/em> is a fully-attributed data model that is dependent upon a specific version of a data persistence technology. The target implementation technology may be a relational DBMS, an XML document, a SQL data storage component, a spreadsheet or any other data implementation option.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS218.png\" alt=\"\"\/><\/p>\n<ul>\n<li>Typically describes data requirements for a single project or application. Sometimes even a portion of an application.\n\t\t<\/li>\n<li>Typically contains 10-1000 tables, although these numbers are highly variable depending on the scope of the data model.\n\t\t<\/li>\n<li>Contains relationships between tables that address cardinality and nullability (optionality) of the relationships.\n\t\t<\/li>\n<li>Designed and developed to be dependent on a specific version of a DBMS, data storage location or technology.\n\t\t<\/li>\n<li>Columns will have datatypes with precisions and lengths assigned.\n\t\t<\/li>\n<li>Tables and columns will have definitions.\n\t\t<\/li>\n<li>Will also include other physical objects such as views, primary key constraints, foreign key constraints, indexes, security roles, store procedures, XML extensions, file stores, etc.\n\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS219.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS220.png\" alt=\"\"\/><br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS221.png\" alt=\"\"\/><\/p>\n<h2>How to Add a table<br \/>\n<\/h2>\n<p>\uf097\uf020When you open a new, blank database, Access automatically creates an empty table. To customize that table, start defining your fields and add data.<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS222.png\" alt=\"\"\/><\/p>\n<h2>Rename a table in a desktop database<br \/>\n<\/h2>\n<ul>\n<li>Table1 is the default name of the first table in a new desktop database. It&#8217;s a good idea to name the table something more meaningful.\n\t\t<\/li>\n<li>On the Quick Access Toolbar, select <strong>Save<\/strong>\n<\/li>\n<li>In the <strong>Table name <\/strong>box, enter a descriptive name.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS223.png\" alt=\"\"\/><\/p>\n<h2>Add a table to a desktop database<br \/>\n<\/h2>\n<ul>\n<li>Add more tables to a database, if you need them, even if you started with a template.\n\t\t<\/li>\n<li>\n<div>On the <strong>Create<\/strong> tab, select <strong>Table<\/strong>.\n\t\t\t<\/div>\n<p>Access adds a new table with the name Table&lt;#&gt;, where &lt;#&gt; is the next sequential, unused number.\n\t\t\t<\/li>\n<li>Rename the table using the procedure in Rename a table in a desktop database, earlier in this module.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS224.png\" alt=\"\"\/><\/p>\n<h2>Save a table<br \/>\n<\/h2>\n<p>\uf097\uf020Before you close your database, to avoid losing the work you&#8217;ve done and the data you&#8217;ve entered, be sure to save your table. When you try to close the database, if you haven&#8217;t saved your work on a table, Access prompts you to save it. Or, at any time, select .<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS225.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS226.png\" alt=\"\"\/><\/p>\n<h2>Add a field by entering data<br \/>\n<\/h2>\n<ul>\n<li>\n<div>In <strong>Datasheet<\/strong> view, enter data in the <strong>Click to Add<\/strong> column of the datasheet.\n\t\t\t<\/div>\n<p>Access creates a new field.\n\t\t\t<\/li>\n<li><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS227.png\" alt=\"\"\/>In the column heading, type a new name for the field.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS228.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS229.png\" alt=\"\"\/><\/p>\n<h2>Change the data type of a field<br \/>\n<\/h2>\n<ul>\n<li>When you add a field by typing data into it, Access sets the field&#8217;s data type based on its contents. View the data type on the <strong>Fields<\/strong> tab, under <strong>Data Type<\/strong>.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS230.png\" alt=\"\"\/>To change the data type: <\/p>\n<ul>\n<li>Select the field.\n\t\t<\/li>\n<li>On the Fields tab, open the <strong>Data Type<\/strong> list and select a data type.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS231.png\" alt=\"\"\/><\/p>\n<h2>Add a field for a specific data type<br \/>\n<\/h2>\n<ul>\n<li>Access validates data as it&#8217;s entered to ensure that it matches the field&#8217;s data type. If you need a specific data format in a field, specify its data type when you create it.\n\t\t<\/li>\n<li>With the table open in <strong>Datasheet<\/strong> view, select <strong>Click to Add<\/strong> and then select a data type\n\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS232.png\" alt=\"\"\/><br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS233.png\" alt=\"\"\/><strong>What are queries?<\/strong><\/p>\n<ul>\n<li>In Access, <em>queries<\/em> are like questions that you ask to find related, even very specific, information in your database.\n\t\t<\/li>\n<li>In Access, a query is a database object. It doesn&#8217;t store data. Instead, it displays data that is stored in tables and it makes that data available for you to work with. A query might show data from one or more tables, from other queries, or from a combination of the two.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS234.png\" alt=\"\"\/><\/p>\n<h2><strong>Create a form<\/strong><br \/>\n\t\t<\/h2>\n<ul>\n<li>You can use the Form tool to create a form with a single mouse-click. When you use this tool, all the fields from the underlying data source are placed on the form. You can start using the new form immediately, or you can modify it in Layout view or Design view to better suit your needs.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS235.png\" alt=\"\"\/><strong>Use the Form tool to create a new form<\/strong><\/p>\n<ul>\n<li>In the Navigation Pane, click the table or query that contains the data you want to see on your form.\n\t\t<\/li>\n<li>On the <strong>Create<\/strong> tab, in the <strong>Forms<\/strong> group, click <strong>Form<\/strong>.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS236.png\" alt=\"\"\/><\/p>\n<h2>Introduction to reports<br \/>\n<\/h2>\n<ul>\n<li>When you use a database, you typically use reports to view, format, and summarize data. For instance, you might create a list-type report to display phone numbers for all your contacts, or a summary report to total up the sales for your company across different regions and time periods.\n\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS237.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS238.png\" alt=\"\"\/><br \/>\n\t\u00a0<\/p>\n<ul>\n<li>E\/R modeling was revolutionary in that, for thefirst time in data processing, data \u2013 not processes \u2013 were at the center of both business analysis and system design. Data could now become a reusable commodity. That providedthe ability to track every person or programusing the unique data elements for anypurpose.\n\t\t<\/li>\n<li>At the same time, Dr. Edgar F. Codd, who in the 1970s was a researcher at IBM, realized that data could potentially also be physically organized and stored independent of any particular automated process, so that multiple processes could share the same data. In otherwords, he too wanted data to be reused for multiple purposes.\n\t\t<\/li>\n<li>Data models can facilitate interaction among the designer, the applications programmer,and the end user.\n\t\t<\/li>\n<li>A well-developed data model can even foster improved understanding of the organization for which the database design is developed.\n\t\t<\/li>\n<li>In short, data models are acommunication tool.\n\t\t<\/li>\n<li>Data model creates simple abstraction for better understanding of a complex real-world data environment.\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS239.png\" alt=\"\"\/><\/p>\n<h2><strong>STANDARD DATA MODELS<\/strong><br \/>\n\t\t<\/h2>\n<p>A standard data model or industry standard data model (ISDM) is a data model that is widely applied in some industry, and shared amongst competitors to some degree. They are often defined by standards bodies, database vendors or operating system vendors.<br \/>\n\tWhen in use, they enable easier and faster information sharing because heterogeneous organizations have a standard vocabulary and pre-negotiated semantics, format, and quality standards for exchanged data.<\/p>\n<ul>\n<li>The more effective standard models have developed in the banking, insurance, pharmaceutical and automotive industries, to reflect the stringent standards applied to customer information gathering, customer privacy, consumer safety, or just in time manufacturing.\n\t\t<\/li>\n<\/ul>\n<p>The standard data models used are:- the popular relational model of database management, but some use the hierarchical model, especially those used in manufacturing or mandated by governments, e.g., the din codes specified by Germany.<\/p>\n<ul>\n<li>\n<div>The most complex data models known are in military use, and consortia such as NATO tend to require strict standards of their members&#8217;\n\t\t\t<\/div>\n<p>equipment and supply databases. However, since they did not share these with non-<br \/>\n\t\t\tNATO competitors, it could be referred to as a Standard model\n\t\t\t<\/li>\n<\/ul>\n<p>Other standard are :-Common Education Data Standards<br \/>\n\t(CEDS),SIF<\/p>\n<ul>\n<li>An emerging area of standard data model is in\n\t\t<\/li>\n<li>the identity card arena, where a vast number\n\t\t<\/li>\n<li>of security engineering solutions for public\n\t\t<\/li>\n<li>spaces, e.g., airports, other public transport,\n\t\t<\/li>\n<li>hospitals, are expected soon to rely on a\n\t\t<\/li>\n<li>standard data model for identifying the card\n\t\t<\/li>\n<li>holder\/user of the facility. This may contain\n\t\t<\/li>\n<li>biometric information or other data that would\n\t\t<\/li>\n<li>be standardized across an entire trade bloc,\n\t\t<\/li>\n<li>e.g., the European Union or the North\n\t\t<\/li>\n<li>American Free Trade Agreement (NAFTA).\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS240.png\" alt=\"\"\/>1<sup>st<\/sup>, 2<sup>nd<\/sup>, and 3<sup>rd<\/sup><\/p>\n<p>\tNormal Forms<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS241.png\" alt=\"\"\/><\/p>\n<h2>Overview<br \/>\n<\/h2>\n<p>\uf097\uf020Today we&#8217;ll talk about:<br \/>\n\t\u25e6 Database Normalization<\/p>\n<ul>\n<li>Data Anomalies Caused by:\n\t\t<\/li>\n<li>\n<div>Update, Insertion, Deletion\n\t\t\t<\/div>\n<p>\u25e6 Brief History\/Overview<br \/>\n\t\t\t\u25e6 1<sup>st <\/sup>Normal Form<br \/>\n\t\t\t\u25e6 2<sup>nd <\/sup>Normal Form \u25e6 3<sup>rd<\/sup> Normal Form<br \/>\n\t\t\t\u25e6 Conclusion<br \/>\n\t\t\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS242.png\" alt=\"\"\/><\/p>\n<h2>Database Normalization<br \/>\n<\/h2>\n<ul>\n<li>The main goal of Database Normalization is to restructure the logical data model of a database to:\n\t\t\t\t<\/li>\n<li>Eliminate redundancy\n\t\t\t\t<\/li>\n<li>Organize data efficiently\n\t\t\t\t<\/li>\n<li>Reduce the potential for data anomalies.\n\t\t\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS243.png\" alt=\"\"\/><\/p>\n<h2>Data Anomalies<br \/>\n<\/h2>\n<\/li>\n<\/ul>\n<ul>\n<li>Data anomalies are inconsistencies in the data stored in a database as a result of an operation such as update, insertion, and\/or deletion.\n\t\t<\/li>\n<li>Such inconsistencies may arise when have a particular record stored in multiple locations and not all of the copies are updated.\n\t\t<\/li>\n<li>We can prevent such anomalies by implementing 7 different level of normalization called Normal Forms (NF)\n\t\t<\/li>\n<li>\n<div>We&#8217;ll only look at the first three. \u263a\n\t\t\t<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS244.png\" alt=\"\"\/><\/p>\n<h2>Brief History\/Overview<br \/>\n<\/h2>\n<ul>\n<li>Database Normalization was first proposed by Edgar F. Codd.\n\t\t\t\t<\/li>\n<li>Codd defined the first three Normal Forms, which we&#8217;ll look into, of the 7 known Normal Forms.\n\t\t\t\t<\/li>\n<li>In order to do normalization we must know what the requirements are for each of the three Normal Forms that we&#8217;ll go over.\n\t\t\t\t<\/li>\n<li>One of the key requirements to remember is that Normal Forms are progressive. That is, in order to have 3<sup>rd<\/sup> NF we must have 2<sup>nd<\/sup> NF and in order to have 2<sup>nd<\/sup> NF we must have 1<sup>st<\/sup> NF.\n\t\t\t\t<\/li>\n<\/ul>\n<p>1<sup>st <\/sup>Normal Form<br \/>\n\t\t\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS245.png\" alt=\"\"\/>The Requirements<\/p>\n<ul>\n<li>\n<div>The requirements to satisfy the 1<sup>st<\/sup> NF:\n\t\t\t\t\t<\/div>\n<p>\u25e6 Each table has a primary key: minimal set of attributes which can uniquely identify a record<br \/>\n\t\t\t\t\t\u25e6 The values in each column of a table are atomic (No multivalue attributes allowed).<br \/>\n\t\t\t\t\t\u25e6 There are no repeating groups: two columns do not store similar information in the same table.\n\t\t\t\t\t<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS246.png\" alt=\"\"\/><\/p>\n<h3>1<sup>st <\/sup>Normal Form Example<br \/>\n<\/h3>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS247.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS248.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS249.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS250.png\" alt=\"\"\/>AdvRoom<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS251.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS252.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS253.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS254.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS255.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS256.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS257.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS258.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>123B<\/td>\n<td>Smith<\/td>\n<td>467<\/td>\n<td>209-0<\/td>\n<td>102-8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS259.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS260.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS261.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS262.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS263.png\" alt=\"\"\/>Un-normalized  Students table:<br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS264.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS265.png\" alt=\"\"\/>Normalized Students table:<\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS266.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS267.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS268.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS269.png\" alt=\"\"\/>AdvRoom<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS270.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS271.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS272.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS273.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS274.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS275.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS276.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS277.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS278.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS279.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS280.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS281.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS282.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS283.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS284.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS285.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>123B<\/td>\n<td>Smith<\/td>\n<td>467<\/td>\n<td>102-8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>2<sup>nd <\/sup>Normal Form<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS286.png\" alt=\"\"\/>The Requirements<\/p>\n<ul>\n<li>\n<div>The requirements to satisfy the 2<sup>nd<\/sup> NF:\n\t\t\t<\/div>\n<p>\u25e6 All requirements for 1<sup>st<\/sup> NF must be met.<br \/>\n\t\t\t\u25e6 Redundant data across multiple rows of a table must be moved to a separate table.<\/p>\n<ul>\n<li>The resulting tables must be related to each other by use of foreign key.\n\t\t\t\t<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS287.png\" alt=\"\"\/>Studen#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS288.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS289.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS290.png\" alt=\"\"\/>AdvRoom<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS291.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS292.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS293.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS294.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>123B<\/td>\n<td>Smith<\/td>\n<td>467<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS295.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS296.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS297.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS298.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS299.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2100.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2101.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2102.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>102-8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2103.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2104.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2105.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2106.png\" alt=\"\"\/>2<sup>nd <\/sup>Normal Form  Example<br \/>\n\tStudents table<br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2107.png\" alt=\"\"\/><br \/>\n\tRegistration table<br \/>\n\t3<sup>rd<\/sup> Normal Form<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2108.png\" alt=\"\"\/>The Requirements<\/p>\n<ul>\n<li>\n<div>The requirements to satisfy the 3<sup>rd<\/sup> NF:\n\t\t\t<\/div>\n<p>\u25e6 All requirements for 2<sup>nd<\/sup> NF must be met.<br \/>\n\t\t\t\u25e6 Eliminate fields that do not depend on the primary key;<\/p>\n<ul>\n<li>That is, any field that is dependent not only on the primary key but also on another field must be moved to another table.\n\t\t\t\t<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2109.png\" alt=\"\"\/><\/p>\n<h3>3<sup>rd<\/sup> Normal Form  Example<br \/>\n<\/h3>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2110.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2111.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2112.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2113.png\" alt=\"\"\/>AdvRoom<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2114.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2115.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2116.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2117.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>123B<\/td>\n<td>Smith<\/td>\n<td>467<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2118.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2119.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2120.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2121.png\" alt=\"\"\/>Students table:<br \/>\n\tStudent table: \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0Advisor table:<\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2122.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2123.png\" alt=\"\"\/><\/td>\n<td>\u00a0<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2124.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2125.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2126.png\" alt=\"\"\/>AdvRoom<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2127.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2128.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2129.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2130.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2131.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2132.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2133.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2134.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2135.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2136.png\" alt=\"\"\/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3>3<sup>rd<\/sup> Normal Form<br \/>\n<\/h3>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2137.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2138.png\" alt=\"\"\/>AdvName<\/td>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2139.png\" alt=\"\"\/>AdvRoom<\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2140.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2141.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2142.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>123B<\/td>\n<td>Smith<\/td>\n<td>467<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2143.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2144.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2145.png\" alt=\"\"\/>Students table: Example Cont.<\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2146.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2147.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2148.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2149.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2150.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2151.png\" alt=\"\"\/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Registration table: \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0Advisor table:<\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td>\n\u00a0<\/p>\n<div>\n<table>\n<tbody>\n<tr>\n<td><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2152.png\" alt=\"\"\/>Student#<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2153.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2154.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2155.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2156.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2157.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2158.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2159.png\" alt=\"\"\/><\/td>\n<\/tr>\n<tr>\n<td>124<\/td>\n<td>102-8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2160.png\" alt=\"\"\/><\/td>\n<td><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2161.png\" alt=\"\"\/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2162.png\" alt=\"\"\/><\/p>\n<h2>Conclusion<br \/>\n<\/h2>\n<p>\uf097\uf020We have seen how Database Normalization can decrease redundancy, increase efficiency and reduce anomalies by implementing three of seven different levels of normalization called Normal Forms. The first three NF&#8217;s are usually sufficient for most small to medium size applications.<br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2163.png\" alt=\"\"\/><\/p>\n<h3>KEYS<br \/>\n\t\t<\/h3>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2164.png\" alt=\"\"\/><br \/>\n\tPrimary Key:  a minimal set of attributes that form a candidate key<br \/>\n\t<em>Any attribute or collection of attributes that functionally determine all attributes in a record is a Candidate Key.<\/em><br \/>\n\t<em>Note:  since no two rows in a relational table can be duplicates, the entire record is always a candidate key.<\/em><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2165.png\" alt=\"\"\/><\/p>\n<h2>Primary Key (C)<br \/>\n<\/h2>\n<ul>\n<li>C determines all attributes\n\t\t<\/li>\n<li>No subset of the attributes in C is a candidate key\n\t\t<\/li>\n<\/ul>\n<p><em>A key consisting of more than one attribute is called a <\/em><br \/>\n\t<em>&#8220;composite key.&#8221;<\/em><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2166.png\" alt=\"\"\/><\/p>\n<h2>Good Primary Keys<br \/>\n<\/h2>\n<ul>\n<li>Do not change over the life of the database\n\t\t<\/li>\n<li>Are not &#8220;intelligent keys&#8221;\n\t\t<\/li>\n<li>Are not too long\n\t\t<\/li>\n<li>Do not consist of too many attributes (3 or fewer is good)\n\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2167.png\" alt=\"\"\/><\/p>\n<h2>Foreign Keys<br \/>\n<\/h2>\n<p>A value in the &#8220;child&#8221; table that matches with the related value in the &#8220;parent&#8221; table.<br \/>\n\tSalesRep(SalesRepNumber, Name)<br \/>\n\t\u00a0\u00a0\u00a0\u00a0  \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0[ \u00a0\u00a0\u00a0\u00a003 \u00a0\u00a0\u00a0\u00a0| Mary Jones ]<br \/>\n\t\u00a0\u00a0\u00a0\u00a0  \u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0[ 124<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2168.png\" alt=\"\"\/> |  \u00a0\u00a0\u00a0\u00a003<br \/>\n\t\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0 ]<br \/>\n\tCustomer(CustomerNumber, SalesRepNumber)<br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2169.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2170.png\" alt=\"\"\/>Entity\/Relationship Modelling<br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2171.png\" alt=\"\"\/><\/p>\n<h2>In This Lecture<br \/>\n<\/h2>\n<p>\uf097\uf020Entity\/Relationship models<br \/>\n\t\u25e6 Entities and Attributes<br \/>\n\t\u25e6 Relationships<br \/>\n\t\u25e6 Attributes<br \/>\n\t\u25e6 E\/R Diagrams<br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2172.png\" alt=\"\"\/><\/p>\n<h2>Database Design<br \/>\n<\/h2>\n<ul>\n<li>Before we look at how to create and use a database we&#8217;ll look at how to design one\n\t\t<\/li>\n<li>\n<div>Need to consider\n\t\t\t<\/div>\n<p>\u25e6 What tables, keys, and constraints are needed?<br \/>\n\t\t\t\u25e6 What is the database going to be used for?\n\t\t\t<\/li>\n<li>\n<div>Conceptual design\n\t\t\t<\/div>\n<p>\u25e6 Build a model independent of the choice of DBMS\n\t\t\t<\/li>\n<li>Logical design\n\t\t<\/li>\n<\/ul>\n<p>\u25e6 Create the database in a given DBMS<\/p>\n<ul>\n<li>\n<div>Physical design\n\t\t\t<\/div>\n<p>\u25e6 How the database is stored in hardware\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2173.png\" alt=\"\"\/><\/p>\n<h2>Entity\/Relationship Modelling<br \/>\n<\/h2>\n<ul>\n<li>E\/R Modelling is used for conceptual design\n\t\t<\/li>\n<\/ul>\n<p>\u25e6 Entities &#8211; objects or items of interest<br \/>\n\t\u25e6 Attributes &#8211; facts about, or properties of, an entity<br \/>\n\t\u25e6 Relationships &#8211; links between entities<\/p>\n<ul>\n<li>\n<div>Example\n\t\t\t<\/div>\n<p>\u25e6 In a University database we might have entities for Students, Modules and Lecturers. Students might have attributes such as their ID, Name, and Course, and could have relationships with Modules (enrolment) and Lecturers (tutor\/tutee)\n\t\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2174.png\" alt=\"\"\/><\/p>\n<h2>Entity\/Relationship Diagrams<br \/>\n<\/h2>\n<ul>\n<li>\n<div>E\/R Models are often represented as E\/R diagrams that\n\t\t\t<\/div>\n<p>\u25e6 Give a conceptual view of the database<br \/>\n\t\t\t\u25e6 Are independent of the choice of<br \/>\n\t\t\tDBMS<br \/>\n\t\t\t\u25e6 Can identify some problems in a design<br \/>\n\t\t\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2175.png\" alt=\"\"\/>\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2176.png\" alt=\"\"\/><\/p>\n<ul>\n<li>\n<div>Entities represent objects or things of interest\n\t\t\t<\/div>\n<p>\u25e6 Physical things like students, lecturers, employees, products<br \/>\n\t\t\t\u25e6 More abstract things like modules, orders, courses, projects\n\t\t\t<\/li>\n<li>\n<div>Entities have\n\t\t\t<\/div>\n<p>\u25e6 A general type or class, such as<br \/>\n\t\t\tLecturer or Module<br \/>\n\t\t\t\u25e6 Instances of that particular type, such as Steve Mills, Natasha Alechina are  instances of Lecturer<br \/>\n\t\t\t\u25e6 Attributes (such as name, email address)\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2177.png\" alt=\"\"\/><\/p>\n<h2>Diagramming Entities<br \/>\n<\/h2>\n<ul>\n<li>\n<div>In an E\/R Diagram, an entity is usually drawn as a box with rounded corners\n\t\t\t<\/div>\n<\/li>\n<li>\n<div>The box is labelled with the name of the class of objects represented by that entity\n\t\t\t<\/div>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2178.png\" alt=\"\"\/>\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2179.png\" alt=\"\"\/><\/p>\n<h2>Attributes<br \/>\n<\/h2>\n<ul>\n<li>\n<div>Attributes are facts, aspects, properties, or details about an entity\n\t\t\t<\/div>\n<p>\u25e6 Students have IDs, names, courses, addresses, \u2026<br \/>\n\t\t\t\u25e6 Modules have codes, titles, credit weights, levels, \u2026\n\t\t\t<\/li>\n<li>\n<div>Attributes have\n\t\t\t<\/div>\n<p>\u25e6 A name<br \/>\n\t\t\t\u25e6 An associated entity<br \/>\n\t\t\t\u25e6 Domains of possible values<br \/>\n\t\t\t\u25e6 Values from the domain for each instance of the entity they are belong to\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2180.png\" alt=\"\"\/><\/p>\n<h2>Diagramming Attributes<br \/>\n<\/h2>\n<ul>\n<li>In an E\/R Diagram attributes may be drawn as ovals\n\t\t<\/li>\n<li>Each attribute is linked to its entity by a line\n\t\t<\/li>\n<li>\n<div>The name of the attribute is written in the oval\n\t\t\t<\/div>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2181.png\" alt=\"\"\/>\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2182.png\" alt=\"\"\/><\/p>\n<h2>Relationships<br \/>\n<\/h2>\n<ul>\n<li>Relationships are an association between two or more entities\n\t\t<\/li>\n<\/ul>\n<p>\u25e6 Each Student takes several Modules<br \/>\n\t\u25e6 Each Module is taught by a Lecturer<br \/>\n\t\u25e6 Each Employee works for a single<br \/>\n\tDepartment<\/p>\n<ul>\n<li>\n<div>Relationships have\n\t\t\t<\/div>\n<p>\u25e6 A name<br \/>\n\t\t\t\u25e6 A set of entities that participate in them<br \/>\n\t\t\t\u25e6 A degree &#8211; the number of entities that participate (most have degree 2)<br \/>\n\t\t\t\u25e6 A cardinality ratio\n\t\t\t<\/li>\n<\/ul>\n<p><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2183.png\" alt=\"\"\/><\/p>\n<h2>Cardinality Ratios<br \/>\n<\/h2>\n<ul>\n<li>Each entity in a relationship can participate in zero, one, or more than one instances of that relationship\n\t\t<\/li>\n<li>This leads to 3 types of relationship\u2026\n\t\t<\/li>\n<li>\n<div>One to one (1:1)\n\t\t\t<\/div>\n<p>\u25e6 Each lecturer has a unique office\n\t\t\t<\/li>\n<li>\n<div>One to many (1:M)\n\t\t\t<\/div>\n<p>\u25e6 A lecturer may tutor many students, but each student has just one tutor\n\t\t\t<\/li>\n<li>\n<div>Many to many (M:M)\n\t\t\t<\/div>\n<p>\u25e6 Each student takes several modules, and each module is taken by several students\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2184.png\" alt=\"\"\/>Diagramming Relationships<\/p>\n<ul>\n<li>Relationships are links between two entities\n\t\t<\/li>\n<li>The name is given in a diamond box\n\t\t<\/li>\n<li>\n<div>The ends of the link show cardinality\n\t\t\t<\/div>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2185.png\" alt=\"\"\/>\n\t\t\t<\/li>\n<\/ul>\n<p>One\u00a0\u00a0\u00a0\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2186.png\" alt=\"\"\/> Many<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2187.png\" alt=\"\"\/><\/p>\n<h2>Removing M:M Relationships<br \/>\n<\/h2>\n<ul>\n<li>Many to many relationships are difficult to represent\n\t\t<\/li>\n<li>We can split a many to many relationship into two one to many relationships\n\t\t<\/li>\n<li>\n<div>An entity represents the M:M relationship\n\t\t\t<\/div>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2188.png\" alt=\"\"\/>\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2189.png\" alt=\"\"\/><\/p>\n<h2>Making E\/R Models<br \/>\n<\/h2>\n<ul>\n<li>\n<div>To make an E\/R model you need to identify\n\t\t\t<\/div>\n<p>\u25e6 Enitities<br \/>\n\t\t\t\u25e6 Attributes<br \/>\n\t\t\t\u25e6 Relationships<br \/>\n\t\t\t\u25e6 Cardinality ratios\n\t\t\t<\/li>\n<li>from a description\n\t\t<\/li>\n<li>\n<div>General guidelines\n\t\t\t<\/div>\n<p>\u25e6 Since entities are things or objects they are often nouns in the description<br \/>\n\t\t\t\u25e6 Attributes are facts or properties, and so are often nouns also<br \/>\n\t\t\t\u25e6 Verbs often describe relationships between entities\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2190.png\" alt=\"\"\/><br \/>\n\tA university consists of a number of departments. Each department offers several courses. A number of modules make up each course. Students enrol in a particular course and take modules towards the completion of that course. Each module is taught by a lecturer from the appropriate department, and each lecturer tutors a group of students<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2191.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; Entities<br \/>\n<\/h2>\n<p>A university consists of a number of <strong>departments<\/strong>. Each department offers several <strong>courses<\/strong>. A number of <strong>modules <\/strong>make up each course. <strong>Students <\/strong>enrol in a particular course and take modules towards the completion of that course. Each module is taught by a <strong>lecturer <\/strong>from the appropriate department, and each lecturer tutors a group of students<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2192.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; Relationships<br \/>\n<\/h2>\n<p>\uf097\u00a0\u00a0\u00a0\u00a0A university consists of a number of departments. Each department <strong>offers <\/strong>several courses. A number of modules <strong>make up <\/strong>each course. Students <strong>enrol in <\/strong>a particular course and <strong>take <\/strong>modules towards the completion of that course. Each module is <strong>taught by <\/strong>a lecturer <strong>from the <\/strong>appropriate department, and each lecturer <strong>tutors <\/strong>a group of students<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2193.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2194.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2195.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2196.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2197.png\" alt=\"\"\/>Example &#8211; E\/R Diagram<br \/>\n\tEntities: Department, Course, Module, Lecturer, Student<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2198.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2199.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2200.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2201.png\" alt=\"\"\/>Example &#8211; E\/R Diagram<br \/>\n\tEach department offers several courses<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2202.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2203.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2204.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2205.png\" alt=\"\"\/>Example &#8211; E\/R Diagram<br \/>\n\tA number of modules make up each courses<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2206.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2207.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2208.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2209.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2210.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2211.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2212.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2213.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2214.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2215.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2216.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2217.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2218.png\" alt=\"\"\/><img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2219.png\" alt=\"\"\/>Example &#8211; E\/R Diagram<br \/>\n\t\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2220.png\" alt=\"\"\/><\/p>\n<h2>Entities and Attributes<br \/>\n<\/h2>\n<ul>\n<li>\n<div>Sometimes it is hard to tell if something should be an entity or an attribute\n\t\t\t<\/div>\n<p>\u25e6 They both represent objects or facts about the world<br \/>\n\t\t\t\u25e6 They are both often represented by nouns in descriptions\n\t\t\t<\/li>\n<li>\n<div>General guidelines\n\t\t\t<\/div>\n<p>\u25e6 Entities can have attributes but attributes have no smaller parts<br \/>\n\t\t\t\u25e6 Entities can have relationships between them, but an attribute belongs to a single entity\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2221.png\" alt=\"\"\/><br \/>\n\tWe want to represent information about products in a database. Each product has a description, a price and a supplier. Suppliers have addresses, phone numbers, and names. Each address is made up of a street address, a city, and a postcode.<br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2222.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; Entities\/Attributes<br \/>\n<\/h2>\n<p>\u00a0<\/p>\n<ul>\n<li>\n<div>Entities or attributes:\n\t\t\t<\/div>\n<ul>\n<li>product\n\t\t\t\t<\/li>\n<li>description\n\t\t\t\t<\/li>\n<li>price\n\t\t\t\t<\/li>\n<li>supplier \uf096\uf020address\n\t\t\t\t<\/li>\n<li>phone number\n\t\t\t\t<\/li>\n<li>name\n\t\t\t\t<\/li>\n<li>street address\n\t\t\t\t<\/li>\n<li>city\n\t\t\t\t<\/li>\n<li>postcode\n\t\t\t\t<\/li>\n<\/ul>\n<\/li>\n<li>Products, suppliers, and addresses all have smaller parts so we can make them entities\n\t\t<\/li>\n<li>The others have no smaller parts and belong to a single entity\n\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2223.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n<p><img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2224.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2225.png\" alt=\"\"\/><br \/>\n\t<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2226.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; Relationships<br \/>\n<\/h2>\n<p>\u00a0<\/p>\n<ul>\n<li>\n<div>Each product has a supplier\n\t\t\t<\/div>\n<p>\u25e6 Each product has a single supplier but there is nothing to stop a supplier supplying many products<br \/>\n\t\t\t\u25e6 A many to one relationship\n\t\t\t<\/li>\n<li>\n<div>Each supplier has an address\n\t\t\t<\/div>\n<p>\u25e6 A supplier has a single address<br \/>\n\t\t\t\u25e6 It does not seem sensible for two different suppliers to have the same address<br \/>\n\t\t\t\u25e6 A one to one relationship\n\t\t\t<\/li>\n<\/ul>\n<p>\u00a0<img decoding=\"async\" align=\"left\" src=\"https:\/\/ecolebooks.com\/nigeria\/wp-content\/uploads\/9jalessonsimages\/100323_1251_AllWeeksSS2227.png\" alt=\"\"\/><\/p>\n<h2>Example &#8211; E\/R Diagram<br \/>\n<\/h2>\n","protected":false},"excerpt":{"rendered":"<p>DATA PROCESSING FIRST TERM SCHEME OF WORK FOR SS TWO weeks Content 1 REVISION 2&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,244],"tags":[],"class_list":["post-2750","post","type-post","status-publish","format-standard","hentry","category-posts","category-first-term-ss2-data-processing"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2750","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=2750"}],"version-history":[{"count":2,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2750\/revisions"}],"predecessor-version":[{"id":2778,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2750\/revisions\/2778"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=2750"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=2750"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=2750"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}