Solved

Incorrect table definition; there can be only one auto column and it must be defined as a key

Posted on 2009-05-04
2
3,244 Views
Last Modified: 2012-05-06
I am attempting to migrate from MS SQL to MYSQL, using the MYSQL Migration Toolkit.  I have generated scripts with the tool that I am running from myPHPadmin.  While some of the CREATE TABLE commands are working, a few of them generate this error:

Incorrect table definition; there can be only one auto column and it must be defined as a key.

My understanding is you cannot have more than one field with auto_increment, and it must be primary key.  Can you not have multiple primary keys but set only one of the to auto_increment?


DROP TABLE IF EXISTS `captain1`.`tblEducation`;
CREATE TABLE `captain1`.`tblEducation` (
  `UserID` INT(10) NOT NULL,
  `EducationID` INT(10) NOT NULL AUTO_INCREMENT,
  `InstituteName` VARCHAR(50) NULL,
  `ProgramName` VARCHAR(50) NULL,
  `LevelObtained` VARCHAR(50) NULL,
  `StudyFrom` DATETIME NULL,
  `StudyTo` DATETIME NULL,
  `GradDate` DATETIME NULL,
  `Skills` VARCHAR(50) NULL,
  `Type` VARCHAR(50) NULL,
  PRIMARY KEY (`UserID`, `EducationID`),
  CONSTRAINT `FK_tblEducation_tblUsers` FOREIGN KEY `FK_tblEducation_tblUsers` (`UserID`)
    REFERENCES `captain1`.`tblUsers` (`UserID`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION
)
ENGINE = INNODB;

Open in new window

0
Comment
Question by:phisherpryce
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 28

Assisted Solution

by:gamebits
gamebits earned 200 total points
ID: 24298088
A PRIMARY KEY is a unique index where all key columns must be defined as NOT NULL. If they are not explicitly declared as NOT NULL, MySQL declares them so implicitly (and silently). A table can have only one PRIMARY KEY. If you do not have a PRIMARY KEY and an application asks for the PRIMARY KEY in your tables, MySQL returns the first UNIQUE index that has no NULL columns as the PRIMARY KEY.

More info here

http://dev.mysql.com/doc/refman/5.1/en/create-table.html
0
 
LVL 17

Accepted Solution

by:
k_murli_krishna earned 300 total points
ID: 24298093
Please refer:
http://www.experts-exchange.com/Database/MySQL/Q_24265504.html

You have to make UserID also as an AUTO_INCREMENT column and have the rest definition as it is and the table should get created.
0

Featured Post

The Ultimate Checklist to Optimize Your Website

Websites are getting bigger and complicated by the day. Video, images, custom fonts are all great for showcasing your product/service. But the price to pay in terms of reduced page load times and ultimately, decreased sales, can lead to some difficult decisions about what to cut.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Password hashing is better than message digests or encryption, and you should be using it instead of message digests or encryption.  Find out why and how in this article, which supplements the original article on PHP Client Registration, Login, Logo…
Introduction This article is intended for those who are new to PHP error handling (https://www.experts-exchange.com/articles/11769/And-by-the-way-I-am-New-to-PHP.html).  It addresses one of the most common problems that plague beginning PHP develop…
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…

691 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