Skip to main content

Posts

Showing posts with the label how to Emptying tables in mysql

Altering Tables ( Emptying Tables )

To remove records from a table without removing the table itself, use the DELETE or TRUNCATE TABLE  statement. Either of the following statements completely empties the named table:   DELETE FROM t;  TRUNCATE TABLE t;  DELETE takes an optional WHERE clause that identifies which records to remove. This is useful when only  a given subset of records from a table need to be deleted. The following statement removes only those  records from t that have a status column value of 'expired', in order by the id column and output limited to  4 rows:   DELETE FROM t WHERE status = 'expired' ORDER BY id LIMIT 4;  TRUNCATE also will reset the metadata held within the format files of the table being truncated ( .frm )  such as the AUTO_INCREMENT starting value.