Introduction to the SQL Database Query
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In this seventh hour, you will learn about database queries, which involve the use of the SELECT statement. The SELECT statement is the most frequently used of all SQL commands after a database's establishment. The SELECT statement allows you to view data that is stored in the database.
The highlights of this hour include
What a database query is
How to use the SELECT statement
Adding conditions to queries using the WHERE clause
Using column aliases
Selecting data from another user's table
What Is a Query?
A query is an inquiry into the database using the SELECT statement. A query is used to extract data from the database in a readable format according to the user's request. For instance, if you have an employee table, you might issue a SQL statement that returns the employee who is paid the most. This request to the database for usable employee information is a typical query that can be performed in a relational database.