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Bug #36812 bind NULL variables generates warning
Submitted: 2006-03-21 12:38 UTC Modified: 2006-11-13 22:11 UTC
From: ce at netage dot bg Assigned:
Status: Closed Package: PostgreSQL related
PHP Version: 5.1.3RC1 OS: linux
Private report: No CVE-ID:
 [2006-03-21 12:38 UTC] ce at netage dot bg
when binding explicit null value there is no problem (see the workarround), but, when the null value is from variable there is a problem (the example is stupid, but is the simplest one representing the problem)

Reproduce code:
CREATE TABLE nullproblem (i integer);

$conn = pg_connect('dbname=test');

$temp1 = null;

$param_list = array($temp1, $temp1, $temp1, );


$param_list = array(is_null($temp1)?null:$temp1, is_null($temp1)?null:$temp1, is_null($temp1)?null:$temp1, );


pg_prepare($conn, 'test', 'INSERT INTO nullproblem VALUES (case when $2::int IS NULL then $3::int else $1::int end)');
pg_execute($conn, 'test', $param_list);

Expected result:
nothing special

Actual result:
Warning: pg_execute(): Query failed: ERROR:  invalid input syntax for integer: "" in test.php on line 10


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 [2006-03-22 18:19 UTC]
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at and the instructions on how to report
a bug at

You declare the parameter is being of type INT and then put NULL into it. Is it any wonder PostgreSQL generates an error?
 [2006-03-23 09:58 UTC] ce at netage dot bg
check the workarround and see how an array of 

$param_list = array(null, null, null);

does NOT generate any error, actually working as expected (so the problem is not at the integer type of the column, because it has the right to be NULL)
 [2006-09-26 22:30 UTC]
Assigned to the maintainer.
 [2006-11-11 14:16 UTC]
This happens because pg_execute() modifies the array values, so $temp1 gets passed a NULL initially, then $temp1 is converted to a string which is why the second time it is passed it fails to execute.

This can be demonstrated by doing var_dump($temp1); before and after the pg_execute() statement.

I don't claim to know PHP internals, but perhaps the fact that it uses convert_to_string() instead of convert_to_string_ex() is the cause?
 [2006-11-13 22:11 UTC]
This bug has been fixed in CVS.

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