Call to a member function exec() on a non-object when doing PDO::exec()

Question

I am working on a PHP script to export/import some database rows from one DB to another.

So far I got this function to make sure the destination table is empty before putting new rows in there:

function truncateTable($conn, $tblname)
{
    echo "Truncating..";
    $query = $conn->exec("TRUNCATE TABLE $tblname") or die("failed!");
    echo "Truncated table $tblname!";
}

However, this is giving me this error:

Call to a member function exec() on a non-object

The connectionstring that gets passed to the function in $conn looks like this:

$con2 = new PDO("mysql:host=$dbs2;dbname=$dbd2",$dbu2,$dbp2);

I call the function like this:

truncateTable($con2, "users");

What am I doing wrong?

I am just learning PDO, so forgive me if this is a very basic question.

Try `$conn->exec(...)` instead. – hafichuk Jan 15 '13 at 19:52 — hafichuk, Jan 15 '13 at 19:52

user1909426 · Accepted Answer · 2013-01-15T19:59:53.623

4

Try this instead, you are passing $conn in to the method, not $q:

function truncateTable($conn, $tblname)
{
    echo "Truncating..";
    $query = $conn->exec("TRUNCATE TABLE $tblname") or die("failed!");
    echo "Truncated table $tblname!";
}

To fix the other issue, use query() instead of exec() :)

edited Jan 15 '13 at 19:59

answered Jan 15 '13 at 19:53

user1909426

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Correct - that was a bummer. However, now I just get "failed!" - any way to see more error info? – Frederik Jan 15 '13 at 19:54

score 3 · Answer 2 · answered Aug 14 '14 at 20:57

One possible culprit may be DB permissions--i.e. does the MySQL user profile have sufficient privileges to TRUNCATE a table? Intuitively that might seem like the same thing as DELETE, but it's not. TRUNCATE requires DROP privileges (http://dev.mysql.com/doc/refman/5.1/en/truncate-table.html).

One frustrating thing about mysqli_query() is that if the web user is not allowed to DROP tables, the "...or die()" part doesn't execute--kind of passive-aggressive, IMO. ;~)

score 2 · Answer 3 · edited Jul 04 '15 at 05:37

2

The argument in the function is $conn, not $q.

edited Jul 04 '15 at 05:37

Saty

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answered Jan 15 '13 at 19:52

Jonathan Kuhn

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Correct. This does however not solve my problem. Now it just prints "failed!" – Frederik Jan 15 '13 at 19:53
@FrederikNielsen does the connected user have DROP priveleges? it is required for TRUNCATE – Jonathan Kuhn Jan 15 '13 at 19:55
It works if I do it via phpMyAdmin - so the query shouldn't be wrong – Frederik Jan 15 '13 at 19:57
1

@FrederikNielsen also, instead of `die("failed!");`, you could use something like `die(print_r($conn->errorInfo(),1));` – Jonathan Kuhn Jan 15 '13 at 19:57

score -1 · Answer 4 · answered May 16 '16 at 01:48

-1

This worked for me:

$clean2 = $db->query( "TRUNCATE TABLE `table`");

Nice and simple.

answered May 16 '16 at 01:48

Natan Coats

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7

Call to a member function exec() on a non-object when doing PDO::exec()

4 Answers4