php - DELETE mutiples table doesn't work -

$sql = "delete t1, t2, t3, t4, t5, t6, t7     bla1 t1, bla2 t2, bla3 t3, bla4 t4, bla5 t5, bla6 t6, bla7 t7   t1.id = t2.id ,   t2.id = t3.id ,   t3.id = t4.id   ,   t4.id = t5.id ,   t5.id = t6.id ,   t6.id = t7.id ,   t1.id = {$_get["id"]}"; 

ok, i'll bite.

you've got sql injection hole in code
here:

t1.id = {$_get["id"]}";  <<-- never inject php `get` sql! 

see answers question: how can prevent sql injection in php?

if want webmaster, knowing sql-injection , xss 2 important things.
learn 2 things , you'll have happy customers.

back business:

mysql delete
have syntax error in delete statement.
delete not follow same syntax select.
select selects columns, delete works on rows, it's mix of metaphors mention columns in delete statement.

see here correct syntax: http://dev.mysql.com/doc/refman/5.5/en/delete.html

because did not explain in question intended do, i'll have guess. looks tying multi-table delete.
e.g. deleting rows multiple interlinked tables.
how , why tables interlinked important, did not state i'll have guess.

multi-table delete manual:

delete [low_priority] [quick] [ignore]
tbl_name[.] [, tbl_name[.]] ...
table_references
[where where_condition]

$stmt = $pdo->prepare('delete t1, t2, t3, t4, t5, t6, t7   (t1.id = t2.id)     , (t2.id = t3.id)     , (t3.id = t4.id)       , (t4.id = t5.id)     , (t5.id = t6.id)     , (t6.id = t7.id)     , (t1.id = :id'); $id = get["id"]; $stmt->execute(array(':id' => $id)); 

note because you're using mysql pdo, immune sql-injection.
see here on info prepared data objects pdo