Segmentation Fault from PHP PDO FreeTDS ODBC execution

Question

I am currently migrating a PHP project from using PHP's mssql library to using the PDO library with FreeTDS. I have modified all of my database calls, but have run into a very strange problem executing the prepared statements on the SQL Server database.

Below is a snippet of code that I am having the problem with.

public static function gift_cards_exist($start_number, $end_number = null) {
    global $sol_donations;
    $db = $sol_donations->get_db();

    $store_id = get_option('pos-store-id', false);
    //$store_id = '01';  // Won't work if value assigned this way
    $payment_method = 'Gift';

    if (empty($end_number)) {
        $end_number = $start_number;
    }

    $query = '
        SELECT * FROM dbo.tblPmtSerialHdr
        WHERE SerialId BETWEEN ? AND ?
        AND   StoreId = ?';
        //AND   PmtMethodId = ?';

    $stmt = $db->prepare($query);
    $stmt->bindParam(1, $start_number, \PDO::PARAM_STR | \PDO::PARAM_INPUT_OUTPUT);
    $stmt->bindParam(2, $end_number, \PDO::PARAM_STR | \PDO::PARAM_INPUT_OUTPUT);
    $stmt->bindParam(3, $store_id, \PDO::PARAM_STR | \PDO::PARAM_INPUT_OUTPUT);
    //$stmt->bindParam(4, $payment_method, \PDO::PARAM_STR | \PDO::PARAM_INPUT_OUTPUT);
    $result = $stmt->execute();

    $result = $stmt->fetchAll(\PDO::FETCH_ASSOC);
    $stmt->closeCursor();

    /* Nothing printed from this
    echo $stmt->errorCode();
    echo '<br />';
    echo $stmt->errorInfo();
    */
    var_dump($result);
    exit();

    if ($result) {
        return true;
    }
    return false;
}

Here is where the problem exists. Running the code in this form (with all of the commented lines remaining commented) results in correct execution of the query with the expected, although not correct for my program, results.

However, if I modified the query to use the second AND statement and uncommented the last bindParam statement to use with the statement, the script will fail causing a segmentation fault. The actual error message that I get in the apache error log is:

[Fri Feb 06 10:43:05.406772 2015] [core:notice] [pid 1415] AH00051: child pid 1541 exit signal Segmentation fault (11), possible coredump in /etc/apache2

I have absolutely no idea why adding this one extra parameter for the prepared statement is causing a problem.

Some extra information about the situation:

FreeTDS is installed correctly and can be used to connect to the database and query the data.

I have tried using both bindParam and bindValue and both give the same results.

I have tried running the statement with and without the bitwise or with PDO::PARAM_INPUT_OUTPUT.

Finally, I checked to make sure that there are no NULL in the record set that should be returned to make sure that NULL values couldn't be the cause.

you should probably talk to the freetds people and report a bug in their software. — Marc B, Feb 06 '15 at 16:53

score 1 · Accepted Answer · answered Feb 06 '15 at 23:48

1

So, it turns out that this is some sort of bug in the FreeTDS ODBC driver. I switch over to using the dblib driver and all of my queries worked correctly with no segmentation faults.

answered Feb 06 '15 at 23:48

BLenau

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score 0 · Answer 2 · answered Oct 20 '16 at 10:12

Had a similar issue where the query I was running through PDO and DBLIB was returning a money type value. The version of DBLIB I'm having to use caused segmentation faults in apache and google lead me to this SO.

Simply casting the money type value to decimal meant I could work around this, while still maintaining decimal precision.

Segmentation Fault from PHP PDO FreeTDS ODBC execution

2 Answers2