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Introduction to SQL - Part 6 - Data Query Language

Data Query Language 

DQL is used to fetch the data from the database. 

It uses only one command: 

SELECT 

a. SELECT: This is the same as the projection operation of relational algebra. It is used to select the attribute based on the condition described by WHERE clause. 

  •     Syntax: 
    • SELECT expressions FROM TABLES WHERE conditions; 
  •     Example: 
    • SELECT emp_name FROM employee WHERE age > 20;

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