Getting an auto-increment id?

[LemonInflux]

OK, I am building my forum, as people know, and have hit a problem. Posting..

 

I can work posting out just fine, that's not a problem. The problem is, however, as follows:

 

When someone creates a topic, the following is executed:

 

$sql = mysql_query("INSERT INTO `reflexproj`.`topics` (`topic_name`, `topic_desc`, `poster`, `forumid`) VALUES ('". $posttitle ."', '". $desc ."', '". $sessionu ."', '". $forum ."');");

 

This inserts the topic into the topic table. However, then this is executed:

 

$sql = mysql_query("INSERT INTO `reflexproj`.`posts` (`poster`, `post`, `topicid`) VALUES ('". $sessionu ."', '". $fp ."' '". $id ."');");

 

This is meant to insert a post into the posts table that starts the topic. However, this is a problem. The problem is, that $id hasn't been defined.

 

My question is this, really: How do I get $id? Basically, I've got to find a way of getting an auto_increment value from a database. Anyone any ideas?

[brettpower]

Sounds like you know what your doing, however, this may be what you need.

 

Auto-incremental ID's are setup in the database directly.  If you are using phpMyAdmin to configure your database make sure that your ID column is set to INT and Extra is set to auto-increment.  Doing this will automatically populate the ID field for you.  Each new record inserted will elevate the ID number by one each time.

 

Be sure to check and make sure that your queries contain the same number of columns that your database has.  You can always echo your queries so you can get a visual confirmation of your success.

[LemonInflux]

I have an ID column..I'm trying to get that id.

[BlueSkyIS]

to get the id of the last inserted record use mysql_insert_id();

[LemonInflux]

I was trying to think of another way around it. If, by an offchance, 2 topics were posted at the same time, wouldn't you end up posting in different topics?

[BlueSkyIS]

every id will be unique. when you insert a record, you'll get the id of the record you inserted, not the id of some other record.

[brettpower]

Is the ID field in the database being populated? Or is the ID field blank in the database? Are you just trying to retrieve it?

[LemonInflux]

The ID is auto increment. I'm trying to find out what it is as I submit the information to the database. If it isn't possible, I'll use BlueSkyIS's idea.

[BlueSkyIS]

unless you specify the id yourself, you don't know what it is until after the record is inserted. after the record is inserted, use mysql_insert_id() to see what value the id was assigned by MySQL.

[LemonInflux]

I tried this idea, but there was a problem. mysql_insert_id always seems to return '1'

[AndyB]

I tried this idea, but there was a problem. mysql_insert_id always seems to return '1'

 

... show us the code you're using to retrieve the value.

[LemonInflux]

<?php
$sql = mysql_query("INSERT INTO `forum`.`topics` (`topic_name`, `topic_desc`, `poster`, `forumid`) VALUES ('". $posttitle ."', '". $desc ."', '". $sessionu ."', '". $forum ."');");
$sql = mysql_query("INSERT INTO `forum`.`posts` (`poster`, `post`, `topicid`) VALUES ('". $sessionu ."', '". $fp ."' '". mysql_insert_id() ."');");
?>

 

[BlueSkyIS]

I tried this idea, but there was a problem. mysql_insert_id always seems to return '1'

 

are you using the function with the parentheses?

 

mysql_insert_id();

 

also, you should know to put or die(mysql_error()) after your mysql_query() calls! 

 

you have bad SQL.