Getting ID after submission

[Arbitus]

So I'm working on this forum and I hit a problem.

 

Right now I have 2 tables for posts and topics.

 

I have a topics table which stores the board_id, topic_title, topic_owner, and of course, the topic ID itself.

 

Then I have the posts table which also stores the topic_title, it's own id, users message and so on

 

	// Insert the information into arbi_topics first
$newtopicsql = "INSERT INTO `arbi_topics` (title,board_id,starter_id) 
		  VALUES ('$topictitle','$boardid','$username')" or die (mysql_error());
mysql_query($newtopicsql) or die (mysql_error());

//Insert the information in arbi_posts second
$newpostsql = "INSERT INTO 'arbi_posts' (topic_id,topic_title,message,post_owner)
				VALUES ('$newID','$topictitle','$topicmessage','$username')" or die (mysql_error());

 

In the first query, it is storing some information in the topic table. While the second query is storing the information in the posts table. Some how I need to get the ID from the topics table into a variable so I can store the topic ID into the posts table.

[revraz]

Are you referring to the last ID inserted ?

 

http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html

[Arbitus]

I can't figure out how to use it, or store it's value in a variable so I can insert it into the next query.

 

// This is the topic table

$newtopicsql = "INSERT INTO `arbi_topics` (title,board_id,starter_id)

  VALUES ('$topictitle','$boardid','$username')" or die (mysql_error());

mysql_query($newtopicsql) or die (mysql_error());

 

 

 

//I need the ID of what I just entered able to be inserted here in topic_id

$newpostsql = "INSERT INTO 'arbi_posts' (topic_id,topic_title,message,post_owner)

VALUES ('$topicid2','$topictitle','$topicmessage','$username')" or die (mysql_error());

mysql_query($newpostsql) or die (mysql_error());

[mmarif4u]

you can use it like:

$topic_id = mysql_insert_id();

 

if topic_id is auto_increment in topic table.

 

Then save that $topic_id in arbi_posts.

 

[Arbitus]

I stumbled across MAX(ID) so I used that.

 

Would it be better to use the mysql_insert_id() ? or is MAX(ID) alright.  It seems to work beautifully

[mmarif4u]

Max will pickup the maximum id form the table, which can be any one (depends).

But mysql_insert_id will pickup id, which is inserted just now.

You can use MAX, its upto u. but better use mysql_insert_id.