eliminar todos los registros de la tabla
DELETE FROM table_name;
eliminar todas las filas de la tabla mysql
-- Quick, no possible rollback
TRUNCATE TABLE my_table;
-- With rollback
DELETE FROM my_table;
COMMIT;
sql eliminar fila de la tabla
DELETE FROM table_name WHERE condition;
eliminar consulta
public function deletedata(){
$this->db->where('id', 2);
$this->db->delete('table_name');
}