MS-SQL 7 versus MS-SQL 2000

Hello there, I have a Serious Problem :( I wrote a web-application that allows database administrators to edit the contents of a database. Not in a phpMyAdmin-like manner, as that is too close to the data for 'normal users' (direct table access). It is more like Microsoft Access (yuk! :)), but in a web-interface. This application is more or less independent of the DBMS that is used. It currently supports MySQL, PostgreSQL, MS-SQL and Sybase. In the MS-SQL case, I have always tested it with version 2000 (or 8), which works fine. One of my customers has MS-SQL 7, and now I suddenly run into problems. The problems have nothing to do with the fact that MS-SQL 7 - like MS-SQL 2000 - is not a real relational DBMS. Whereas in MS-SQL 2000 you can use referential integrity to cascade deletetion and such, in MS-SQL 7 this has to be done by hand. I'm perfectly aware of this, so this is not where my problems lie. Strangely enough, my problem seems to be with PHP. Let me explain the steps taken when I insert a new record: - A form is posted, containing values for a new record - The new record is inserted into the database - If a new record was succesfully created, I redirect to a new page, showing the newly inserted record - If the record could not be inserted, I redisplay the insertion form and show some meaningful error message like 'not all fields have a value' or 'unique field already exists'. This sounds pretty logical and simple I think, and so is the implementation: // For clarity: this is a class-method, not a function... function handleInsert() { $command = $this->table->getInsertCommand(); if ($command->run()) { $record = &$command->getInsertedRecord(); $url = new Url($_SERVER['PHP_SELF']); $url->setParameter('key', $record->getKey()); header('Location: ' . $url->getUrl()); } $this->setMessage('Error: ' . $command->getErrorMessage()); $this->buildInsertWindow(); } Even though nobody here knows about the classes I use, I think the idea is pretty clear. Also, it works very well with MySQL, PostgreSQL, MS-SQL 2000 and Sybase. As soon as I run this code on MS-SQL 7, things go wrong: everytime I do an insert I get an error 'This statement has been cancelled', but the record is inserted successfully!. I thought that this is very strange, so I dug a little deeper. It turns out that the code above is executed many times instead of just once: the first time the record is inserted successfully, but the script simply continues to insert new records. If one of the fields in the table is unique, this means that the second time the code is executed, the insertion fails, resulting in mentioned error message. If there is no unique key in a table (or the unique key is an AUTONUMBER or something), the record is inserted over and over again until the script times out. This also happens if I do something different than an insert, like a delete: the browser hangs for the maximum execution time (30 seconds) and PHP times out. The same code is being executed over and over again, deleting the same record over and over again (which doesn't work, naturally). I've done some searching, and I've made the following observations: - The "header('Location :' ...')" works fine. - The URL for the new page is based on the one from the current page. In my implementation that means that whether to execute an insertion, deletion or update depends on the POST-parameters passed to the script. - Apparantly, the POST-variables for the current page are saved and passed on to the next page when I execute the header-function, so, in effect, the script opens itself again. The strange thing is: this seems to have nothing to do with the DBMS I'm using, but with PHP instead. However I know that this isn't true, as the code runs fine with different DBMS's! To be honest, I'm completely baffled. I've been looking into this for a week now, and still have no idea what to do. I'm seriously considering to tell my customer to upgrade to MS-SQL 2000, or to just forget about the whole thing. I hope I'm not the first to experience this problem, so hopefully somebody out here can nudge me in the right direction. Thanks in advance! Vincent