set primary key in existing table and field

Posted on 2006-07-16
Medium Priority
Last Modified: 2008-02-26
hi, no matter how much i google search this, i cant find the answer.

how do i set the primary key and auto_increment on an already existing field in a table.

For the history, im copying 35 tables in a database with different table names using:

$table = "CREATE TABLE IF NOT EXISTS ".$username."_banner SELECT * FROM default_banner";

but this does not copy over the primary key and auto_increment settings.
Question by:Erron
  • 2
LVL 35

Accepted Solution

Raynard7 earned 500 total points
ID: 17119021
alter table `test`.`tablename1` change `a` `a` int (10)   NOT NULL AUTO_INCREMENT , add primary key (`a` )

Will change a table (tablename1) in the test schema -
it will change field `a` to an autoincrement field and will be the primary key.
LVL 35

Expert Comment

ID: 17119022
If there are null values it will not work

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

These days socially coordinated efforts have turned into a critical requirement for enterprises.
The title says it all. Writing any type of PHP Application or API code that provides high throughput, while under a heavy load, seems to be an arcane art form (Black Magic). This article aims to provide some general guidelines for producing this typ…
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.

627 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question