从表中删除所有记录
DELETE FROM table_name;
删除表mysql中的所有行
-- Quick, no possible rollback
TRUNCATE TABLE my_table;
-- With rollback
DELETE FROM my_table;
COMMIT;
sql从表中删除行
DELETE FROM table_name WHERE condition;
删除查询
public function deletedata(){
$this->db->where('id', 2);
$this->db->delete('table_name');
}