Direct Query delete with error: SQLSTATE[21000]: Cardinality violation

Question

I'm trying to delete some data from database with direct sql query, but I get a Cardinality violation.

$conn = Mage::getSingleton('core/resource')->getConnection('core_write');
$sql = "DELETE * FROM catalog_product_super_link WHERE parent_id =" . 
$_product->getId() . "AND product_id = ". $child_id . ";";
$conn->query($sql);

And the full error is:

SQLSTATE[21000]: Cardinality violation: 1241 Operand should contain 1 column(s), query was: SELECT `catalog_product_entity`.* FROM `catalog_product_entity` WHERE (entity_id ='1', '3', '4', '5', '1431', '1432', '1433', '1434', '1435', '1436', '1437', '1438', '1439', '1440', '1441', '1442')

I'm not very good with sql queries... so I need a bit of help here

edit: catalog_product_super_link table

link_id  -  product_id  -  parent_id
1           1              2
2           3              2
3           4              2
4           5              2
5           6              7
6           8              7
7           9              7
8           10             7
9           11             7
10          12             7
11          13             7
15599       13             7182
12          14             7
15600       14             7182
13          15             7
14          16             7
15          17             7
16          18             7
17          19             7
18          20             7
19          21             7
20          22             7
21          23             24
22          25             24
23          26             24
24          27             24
25          28             24
26          29             24
27          30             24
...         ...            ...

Answer 1

Try this code. I've make some changes in query.

$sql = "DELETE * FROM catalog_product_super_link WHERE parent_id = " . (int)$_product->getId() . "AND product_id = " . (int)$child_id;

Answer 2

$sql = "SET FOREIGN_KEY_CHECKS=0; DELETE * FROM catalog_product_super_link WHERE parent_id = " . (int)$_product->getId() . " AND product_id = " . (int)$child_id."; SET FOREIGN_KEY_CHECKS=1;";

the query is correct but the query cannot find product with id 7 for example you must disable FOREIGN_KEY_CHECKS before execute query test my query