Difference between DELETE, TRUNCATE, DROP in SQL

[Muthuganesh]

Hi,

            Thought of sharing,

The DELETE command is used to remove rows from a table. A WHERE clause can be used only to remove some rows. If no WHERE condition is specified, all rows will be removed. After performing a DELETE operation you need to COMMIT or ROLLBACK the transaction to make the change permanent or to undo it.

TRUNCATE removes all rows from a table. The operation cannot be rolled back. As such, TRUCATE is faster and doesn't use as much undo space as a DELETE.

The DROP command removes a table from the database. All the tables' rows, indexes and privileges will also be removed. The operation cannot be rolled back.

 
DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. Therefore DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.


M.Muthuganesh
Navagate

[admin]

Dear Ganesh,

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Pal