A database is an organized collection of information. A simple example of a database are like your telephone directory, recipe book etc. |
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A Relational model is the basis for any relational database management system (RDBMS). A relational model has mainly three components: |
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1) A collection of objects or relations,. |
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2) Operators that act on the objects or relations. |
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3) Data integrity methods. |
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To design a database we need three things: |
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1). Table |
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2). Rows |
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3). Columns |
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A table is one of the most important ingredient to design the database. It is also known as a relation, is a two dimensional structure used to hold related information. A database consists of one or more tables. |
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A table contains rows : Rows is a collection of instance of one thing, such as the information of one employee. |
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A table contains the columns: Columns contains all the information of a single type. Each column in a table is a category of information referred to as a field. |
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One item of data, such as single phone number of a person is called as a Data Value. |