Using the UPDATE operation clauses

The PostgreSQL UPDATE query is used to modify the existing records in a table. You can use the WHERE clause with the UPDATE query to update selected rows; otherwise, all the rows will be updated.

The basic syntax of the UPDATE query with the WHERE clause is as follows:

UPDATE table_name
SET column1 = value1, column2 = value2...., columnN = valueN
WHERE [condition];

You can combine n number of conditions using the AND or OR operators.

The following is an example that will update SALARY for an employee whose ID is 6:

UPDATE employee SET SALARY = 15000 WHERE ID = 6; 

This will update the salary to 15000 whose ID = 6.