apagar todos os registos da tabela
DELETE FROM table_name;
apagar todas as linhas da tabela mysql
-- Quick, no possible rollback
TRUNCATE TABLE my_table;
-- With rollback
DELETE FROM my_table;
COMMIT;
SQL apagar a linha da tabela
DELETE FROM table_name WHERE condition;
apagar a pesquisa
public function deletedata(){
$this->db->where('id', 2);
$this->db->delete('table_name');
}