What is use of MySQL "WHERE" Clause??

MySQL WHERE Clause is used with SELECT, INSERT, UPDATE and DELETE clause to filter the results. It specifies a specific position where you have to do the operation.

Syntax:

WHERE conditions;  

Parameter:

conditions: It specifies the conditions that must be fulfilled for records to be selected.

MySQL WHERE Clause with single condition

Let's take an example to retrieve data from a table "officers".

Table structure:

Execute this query:

SELECT *  

FROM officers  

WHERE address = 'Mau';  

Output:

MySQL WHERE Clause with AND condition

In this example, we are retrieving data from the table "officers" with AND condition.

Execute the following query:

SELECT *  

FROM officers  

WHERE address = 'Lucknow'  

AND officer_id < 5;  

Output:

WHERE Clause with OR condition

Execute the following query:

SELECT *  

FROM officers  

WHERE address = 'Lucknow'  

OR address = 'Mau';  

Output:

MySQL WHERE Clause with combination of AND & OR conditions

You can also use the AND & OR conditions altogether with the WHERE clause.

See this example:

Execute the following query:

SELECT *  

FROM officers  

WHERE (address = 'Mau' AND officer_name = 'Ajeet')  

OR (officer_id < 5);  

Output: