DELETE [LOW_PRIORITY] FROM tbl_name [WHERE where_clause] [LIMIT rows]
This query deletes all rows from the specified table, unless the optional (but desirable!) WHERE or LIMIT clauses are specified. The WHERE clause works the same way as its twin in the SELECT query (see "SELECT"). The LIMIT clause simply lets you specify the maximum number of rows to be deleted.
The LOW_PRIORITY option causes the query to wait until there are no clients reading from the table to perform the operation.