Explain WHERE Clause in SQL

The WHERE clause in SQL is used to filter records that meet specific conditions. It allows you to specify criteria for selecting records from a table.

Basic Syntax

SELECT column1, column2, ...
FROM table_name
WHERE condition;

Example Table

Let's use the same Employees table:

Query to Filter by Department

To get all employees from the "Sales" department, you can use the following query:

SELECT *
FROM Employees
WHERE Department = 'Sales';

Output:

Query to Filter by Age

To get all employees who are 30 years old, you can use the following query:

SELECT *
FROM Employees
WHERE Age = 30;

Output:

Query to Filter by Salary

To get all employees with a salary greater than 55000, you can use the following query:

SELECT *
FROM Employees
WHERE Salary > 55000;

Output:

Query to Filter by Multiple Conditions

To get all employees from the "Marketing" department who are older than 25, you can use the following query:

SELECT *
FROM Employees
WHERE Department = 'Marketing' AND Age > 25;

Output:

Query to Filter Using OR Condition

To get all employees who are either in the "HR" department or have a salary greater than 55000, you can use the following query:

SELECT *
FROM Employees
WHERE Department = 'HR' OR Salary > 55000;

Output:

In these examples, the WHERE clause is used to specify the conditions that the records must meet in order to be included in the results. This allows for more precise data retrieval based on specific criteria.