PostgreSQL - DELETE Query
The PostgreSQL DELETE Query is used to delete the existing records from a table. You can use WHERE clause with DELETE query to delete selected rows, otherwise all the records would be deleted.
Syntax:
The basic syntax of DELETE query with WHERE clause is as follows:
DELETE FROM table_name WHERE [condition];
You can combine N number of conditions using AND or OR operators.
Example:
Consider the table COMPANY having records as follows:
# select * from COMPANY; id | name | age | address | salary ----+-------+-----+-----------+-------- 1 | Paul | 32 | California| 20000 2 | Allen | 25 | Texas | 15000 3 | Teddy | 23 | Norway | 20000 4 | Mark | 25 | Rich-Mond | 65000 5 | David | 27 | Texas | 85000 6 | Kim | 22 | South-Hall| 45000 7 | James | 24 | Houston | 10000 (7 rows)
Following is an example, which would DELETE a customer whose ID is 7:
testdb=# DELETE FROM COMPANY WHERE ID = 2;
Now, COMPANY table will have the following records:
id | name | age | address | salary ----+-------+-----+-------------+-------- 1 | Paul | 32 | California | 20000 3 | Teddy | 23 | Norway | 20000 4 | Mark | 25 | Rich-Mond | 65000 5 | David | 27 | Texas | 85000 6 | Kim | 22 | South-Hall | 45000 7 | James | 24 | Houston | 10000 (6 rows)
If you want to DELETE all the records from COMPANY table, you do not need to use WHERE clause with DELETE queries, which would be as follows:
testdb=# DELETE FROM COMPANY;
Now, COMPANY table does not have any record because all the records have been deleted by DELETE statement.