SQL WHERE Clause

• The WHERE clause is used to explicitly filter out only those records that meet the conditions specified by you. This saves time, effort and complexity.
• Using the WHERE clause makes specified data aggregation a lot easier
• In fetching these relational data items, the WHERE clause in SQL is used. This is responsible for selecting only those data items that correspond to the mentioned conditions.
• This is done to specifically filter out particular columns.

Syntax:

SELECT column_ name
FROM table_ name
WHERE condition;

• Operators in the WHERE Clause help you to specify the various conditions that you would like to query from a database.

Operators used in WHERE to select desired columns for a record are:

Examples of WHERE Clause Operators:

Let's consider an EMPLOYEES table containing information on employees working in a firm distributed across India.

Example:

1. Where Clause with the EQUAL Operator:

This is used to display only those records which have values equal to the values specified.

Example:

SELECT ID, NAME
FROM EMPLOYEES
WHERE AGE=32;

• Above, the code is used to fetch the ID and NAME values for those employees wherein the age of the employee is equal to 32 

Output:

From the table, you can see that employee Roshani meets the given criteria.

2. WHERE Clause with the LESS THAN and GREATER THAN Operators:

These shall be used to display only those records that have values lesser than and greater than the values specified respectively.

Example:

SELECT ID, NAME
FROM EMPLOYEES
WHERE SALARY <20000;

• Above, the code is used to fetch the ID and NAME values for those employees wherein the salaries of the employees are less than Rs. 20000.

Output:

From the table, you can see that employees Seema Kapoor and Abhi Kumar meet the given criterion.