Deleting data in SQL

Deleting records

We use DELETE to delete existing records in a table. Once this is applied, the records are permanently deleted.

To delete all records whilst maintaining the table:

DELETE FROM sales

We can also use TRUNCATE to achieve this. It is faster but it doesn’t keep a log of each deletion:

TRUNCATE TABLE sales

To delete a specifc entry by field:

DELETE FROM sales WHERE sale_id = 1;

Deleting tables

We use DROP to remove an entire table. This will delete the table definition, and all the data, indexes, triggers, constraints and permission specifications for that table.

DROP TABLE sales