How to PostgreSQL- Update & Delete Query
This PostgreSQL tutorial explains how to use the UPDATE & DELETE Query Statements with syntax and examples. PostgreSQL UPDATE command will modify any field value of any PostgreSQL table. The DELETE statement is used to delete records from a table.
PostgreSQL UPDATE Statement
The PostgreSQL UPDATE statement is used to change or modify the existing records in a database table. It is typically used in conjugation with the WHERE clause to apply the changes to only those records that match specific criteria. The basic syntax of UPDATE query with WHERE clause is as follows:
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE [condition];
column1, column2: Name of column(s) to be updated.
value1, value2: New value(s).
WHERE conditions are used to filter the rows returned from the UPDATE statement.
Consider the table payroll having following records:
The following example updates the designation of a payroll record in the payroll table that matches firstname=’Habeeb’ and lastname=’Rahman’.
UPDATE payroll SET designation = 'Administrator' WHERE firstname = 'Habeeb' AND lastname = 'Rahman';
PostgreSQL DELETE Statement
The PostgreSQL DELETE statement is used to delete a single record or multiple records from a table. You can use WHERE clause with DELETE query to delete selected rows, otherwise, all the records would be deleted. The following is a basic syntax of DELETE query with WHERE clause.
DELETE FROM table_name WHERE [condition];
DELETE FROM payroll WHERE lastname = 'Yakkiparamban' AND firstname = 'Anwar';
This above example would delete a record from the payroll table where the lastname is Yakkiparamban and firstname is Anwar.