[SOLVED] How to check id

[nathanmaxsonadil]

Hi,

 

I was wondering how to get the id that has the biggest number and then add 1 to it so I can have an id field

 

id    name

1    test

2    test1

 

 

[matthewhaworth]

If you're using MySQL, though I'm sure it's possible in other DBMS... you can add something named 'auto_increment' onto the field and the database deals with that for you.

[nathanmaxsonadil]

thanks

[nathanmaxsonadil]

how would I do that?

I searched in google bu no luck.

[nathanmaxsonadil]

never mind found it in the extra tab in phpmyadmin 

[Fadion]

If u have phpmyadmin (which u should have) edit the id column, go to extras and select auto_increment.

 

EDIT: didnt see found it by yourself 

[nathanmaxsonadil]

ALTER TABLE `mytbtest` CHANGE `id` `id` VARCHAR( 255 ) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL AUTO_INCREMENT

 

MySQL said: Documentation

#1063 - Incorrect column specifier for column 'id'

[Ken2k7]

Wow...you just love to close and open this topic.

 

Just do this to save all the troubles:

 

In your script where you want to insert the id, put this

 

$query = mysql_query("SELECT * FROM table");

$row = mysql_num_rows($query) + 1;

 

$row will have the next available id number.

[nathanmaxsonadil]

k thanks 

[matthewhaworth]

No, don't take the easy way out, it'll prove terribly inefficient.  What if you delete a record so you only have 6 records but the latest id is 7? It'll try to add 7 again and result in an error.

 

http://dev.mysql.com/doc/refman/5.0/en/example-auto-increment.html

 

phpMyAdmin should deal with it for you.  It works best for primary keys, and I'm assuming iD will be your primary key .

[nathanmaxsonadil]

thanks I had to make it a primary...

[Fadion]

ALTER TABLE `mytbtest` CHANGE `id` `id` INT( 10 ) NOT NULL AUTO_INCREMENT PRIMARY KEY

 

EDIT: lol im always posting after u get solve it by yourself  :-\

[Ken2k7]

Well for my method, it's not hard to fix the id numbers after you deleted something. A for/while loop should fix everything.

 

It's like re-updating the id column.

[matthewhaworth]

Well for my method, it's not hard to fix the id numbers after you deleted something. A for/while loop should fix everything.

 

It's like re-updating the id column.

 

What if you had thousands of users?  It's a big request on the server every time someone deletes an account.  Also, a solution has already been provided my DBMS's, so 'why reinvent the wheel'.  I hear that said all over these forums.

[Ken2k7]

 

What if you had thousands of users?  It's a big request on the server every time someone deletes an account.  Also, a solution has already been provided my DBMS's, so 'why reinvent the wheel'.  I hear that said all over these forums.

Point well made.

[nathanmaxsonadil]

also if 2 people went to the page at the same time.