Deleting Rows

The Deleting Rows section describes the following:

• Deleting selected rows

• Deleting all rows

Deleting Selected Rows

You can delete rows in a table selectively using the DELETE command. You must include a table name and a WHERE clause to specify the rows to delete, as shown in the following example:

test=> DELETE FROM cool_animals WHERE weight is null;

executed
master=> SELECT  * FROM cool_animals;
1,Dog                 ,7
2,Possum              ,3
3,Cat                 ,5
4,Elephant            ,6500
5,Rhinoceros          ,2100

5 rows

Deleting All Rows

You can delete all rows in a table using the TRUNCATE command followed by the table name, as shown in the following example:

test=> TRUNCATE TABLE cool_animals;

executed

Note

While using the TRUNCATE command will both delete rows from a table and physically remove data from your disk, using the DELETE command will logically delete rows from a table. To remove data from your disk after using the DELETE command, use CLEAN UP.

For more information, see the following:

• Deleting selected rows - DELETE

• Deleting all rows - TRUNCATE