Description
The SQL keyword WHERE is used to specify conditions to select specific records from a database, from one or more tables.
- It can be used on different types of SQL statements, like SELECT, UPDATE, DELETE, etc.,
Operators Allowed on WHERE Clause
SQL supports a number of different types of operators that can be used in the WHERE clause, and here is a list of the most commonly used.
See SQL Operators for more details on operators.
| Operator | Description | Example |
| = | Equal | WHERE salary = 20000 |
| > | Greater than | WHERE salary > 20000 |
| < | Less than | WHERE salary < 20000 |
| >= | Greater than or equal | WHERE salary >= 20000 |
| <= | Less than or equal | WHERE salary <= 20000 |
| LIKE | Simple pattern matching | WHERE employee_name LIKE 'Tony%' |
| IN | Check whether a specified value matches any value in a list or subquery | WHERE employee_id IN (1,2,3) |
| BETWEEN | Check whether a specified value is within a range of values | WHERE employee_id BETWEEN 1 AND 3 |
SELECT With WHERE
The below SQL fetches records from a table based on the WHERE conditions.
SELECT * FROM employees
WHERE employee_id IN (1,2,3,4,5);UPDATE With WHERE
The below SQL updates the table records based on the WHERE conditions.
UPDATE employees
SET salary = 20000
WHERE employee_id IN (1,2,3,4,5);DELETE With WHERE
The below SQL deletes the table records based on the WHERE conditions.
DELETE employees
WHERE employee_id IN (1,2,3,4,5);