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
3,169 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
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

U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Please help me with my database modeling 7 38
mySql Syntax 7 44
MySQL Init Waits 25 85
insert into database through form with dynamic fields. 2 6
As a database administrator, you may need to audit your table(s) to determine whether the data types are optimal for your real-world data needs.  This Article is intended to be a resource for such a task. Preface The other day, I was involved …
Introduction Since I wrote the original article about Handling Date and Time in PHP and MySQL (http://www.experts-exchange.com/articles/201/Handling-Date-and-Time-in-PHP-and-MySQL.html) several years ago, it seemed like now was a good time to updat…
Along with being a a promotional video for my three-day Annielytics Dashboard Seminor, this Micro Tutorial is an intro to Google Analytics API data.
As a trusted technology advisor to your customers you are likely getting the daily question of, ‘should I put this in the cloud?’ As customer demands for cloud services increases, companies will see a shift from traditional buying patterns to new…

863 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

Need Help in Real-Time?

Connect with top rated Experts

22 Experts available now in Live!

Get 1:1 Help Now