PostgreSQL DELETE
The DELETE Statement
The DELETE statement is used to delete existing records in a table.
Note: Be careful when deleting records in a table!
Notice the WHERE clause in the
DELETE statement.
The WHERE clause specifies which record(s) should be deleted.
If you omit the WHERE clause,
all records in the table will be deleted!.
To delete the record(s) where brand is 'Volvo', use this statement:
Example
Delete all records where brand is 'Volvo':
DELETE FROM cars
WHERE brand = 'Volvo';
Result
DELETE 1
Which means that 1 row was deleted.
Display Table
To check the result we can display the table with this SQL statement:
Delete All Records
It is possible to delete all rows in a table without deleting the table. This means that the table structure, attributes, and indexes will be intact.
The following SQL statement deletes all rows in the cars
table, without deleting the table:
Example
Delete all records in the cars table:
DELETE FROM cars;
Result
DELETE 3
Which means that all 3 rows were deleted.
Display Table
To check the result we can display the table with this SQL statement:
TRUNCATE TABLE
Because we omit the WHERE clause in the
DELETE statement above, all records will be deleted from the
cars table.
The same would have been achieved by using the
TRUNCATE TABLE statement:
Example
Delete all records in the cars table:
TRUNCATE TABLE cars;
Result
TRUNCATE TABLE
Display Table
To check the result we can display the table with this SQL statement:
