PHP MYSQL Insert语句在FOR循环中挂起

Question

I have spent many hours debugging, and scouring the internet for a solution to this unusual problem. Heres the deal:

I am working on a Work Order Submission and Tracking system. There are two databases involved:

1. The database where the submissions data gets posted, which is located on the same physical machine, but on a separate virtual machine as the webserver serving the php. They are on the same class C subnet.
2. The database of our tracking system. Located on a different physical server on a different IP altogether, also a virtual machine.

Our work order system allows for multiple 'services requested', stored in an array. In our sumbissions database, this is stored as a comma separated string, ie "40,60,70" but in our tracking system database, each 'service requested' needs a separate entry, as to allow the different aspects of the project to be tracked and completed at different times, by different staff.

THE PROBLEM IS: When I place my second insert statement, the one destined for the tracking database, in a for loop, it completely hangs, and takes maybe 5 to 15 minutes, before it passes that point in the code, and sends the confirmation email. The data does not get inserted either.

When I take it out of the for loop and simply do one insert in the submissions database and one insert into the tracking system, it works fine.

First, Ill post the code that works, but only posts one 'service' to the tracking system:

 public function insertOrder()
{
    $services = implode( ',', $this->model->chk );
    $curdate = $this->model->getMySQLDate( $this->model->curdate );
    $dueDate = $this->model->getMySQLDate( $this->model->dueDate );

    $sql = "INSERT INTO orders VALUES(DEFAULT,
            {$this->sanitize($services)},
            {$this->sanitize($curdate)},
            {$this->sanitize($this->model->submittedBy)},
            {$this->sanitize($this->model->shortDesc)},
            {$this->sanitize($this->model->projDetails)},
            {$this->sanitize($dueDate)},
            {$this->sanitize($this->model->dueDateNotes)},
            {$this->sanitize( $this->model->approveBy)},
            {$this->sanitize( $this->model->cost )} )";

    $this->execute( $sql );

    $this->convertServicesToTracks();
    $notes = $this->model->getTracksNotes();
    $dueDate = $dueDate.' 12:00:00';
    $shortDescNoQuotes = str_replace("\"","'",$this->model->shortDesc);

    $sqlTracks = "INSERT INTO todos VALUES(DEFAULT,
            {$this->sanitizeTracks($this->model->chk[0])},
            NULL,
            {$this->sanitizeTracks($shortDescNoQuotes)},
            {$this->sanitizeTracks($notes)},
            now(),
            {$this->sanitizeTracks($dueDate)},
            NULL,
            12,
            NULL,
            'active',
            NULL,
            now() );";

    //echo $sqlTracks;

    $this->executeTracks( $sqlTacks );
}    private function executeTracks( $sql )
{
    $db = $this->getTracksDB( );


    $this->check4Error( $db, $sql );

    return $result;
}

private function getTracksDB()
{
    if (!$this->tracksdb) $this->tracksdb = new mysqli(AbstractSQL::TRACKS_HOST, AbstractSQL::USER, AbstractSQL::PASS, AbstractSQL::TRACKS_SCHEMA);
    return $this->tracksdb;
}

private function convertServicesToTracks()
{
   //converts submission data to tracking system data
}



private function sanitizeTracks($arg)
{
    if (!isset($arg)) return "NULL";
    if (is_numeric($arg) && !is_double( $arg) ) return $arg;
    return "'{$this->getTracksDB()->escape_string($arg)}'";
}

When I add this simple for loop around the second INSERT statement, it hangs, even if the array only has one item!

    for($i = 0; $i < count($this->model->chk); ++$i)
    {
        $sqlTracks = "INSERT INTO todos VALUES(DEFAULT,
            {$this->sanitizeTracks($this->model->chk[$i])},
            NULL,
            {$this->sanitizeTracks($shortDescNoQuotes)},
            {$this->sanitizeTracks($notes)},
            now(),
            {$this->sanitizeTracks($dueDate)},
            NULL,
            12,
            NULL,
            'active',
            NULL,
            now() );";

    //echo $sqlTracks;

    $this->executeTracks( $sqlTacks );
    }

Any help would be greatly appreciated. And I apologize for the long code snippets!!

Answer 1

Is it iterating through the for loop? I see you have an echo, did that write anything out? How many items does it have to iterate through? 5 min seems like a long time but if there are a lot of items that could be why it's taking so long. Are you seeing any errors in your logs?

Something you might try is hold the count in a variable so it doesn't have to calculate that each time. It might speed up your for loop but I'm not sure it will insert the data.

for($i = 0, $count = count($this->model->chk); $i < $count; ++$i)
    {
        $sqlTracks = "INSERT INTO todos VALUES(DEFAULT,
            {$this->sanitizeTracks($this->model->chk[$i])},
            NULL,
            {$this->sanitizeTracks($shortDescNoQuotes)},
            {$this->sanitizeTracks($notes)},
            now(),
            {$this->sanitizeTracks($dueDate)},
            NULL,
            12,
            NULL,
            'active',
            NULL,
            now() );";

    //echo $sqlTracks;

    $this->executeTracks( $sqlTacks );
    }

I found this in the PHP for loop reference: http://php.net/manual/en/control-structures.for.php

Answer 2

Well, this may not be the problem, but shouldn't you generally use a foreach loop to avoid hitting parts of the array that may not exist? There is more about this here . If you loop through an empty index, it would break your SQL statement. Like this:

foreach($this->model->chk as $val)