MySQL alter table add column with primary key syntax error

Question

I'm trying to add a column to one of of my database tables, but there is a syntax error and I can't seem to find the problem...

My current database table looks like this:

component   +  tag_id  +  item_id
------------|----------|-----------
com_content |    23    |    2642
com_content |    26    |    3481
com_content |    35    |    1868
com_content |    85    |    5827
com_content |    89    |    7882

I want it to look like this, where 'id' is auto increment and all columns part of the primary key

 id  +  component   +  tag_id  +  item_id
-----|--------------|----------|-----------
  1  |  com_content |    23    |    2642
  2  |  com_content |    26    |    3481
  3  |  com_content |    35    |    1868
  4  |  com_content |    85    |    5827
  5  |  com_content |    89    |    7882

This is my query:

DROP PRIMARY KEY
ALTER TABLE gitags_items
ADD COLUMN id INT NOT NULL AUTO_INCREMENT FIRST
PRIMARY KEY (id,component,tag_id,item_id)

However I'm getting this error message:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'PRIMARY KEY ALTER TABLE gitags_items ADD COLUMN id INT NOT NULL AUTO_INC' at line 1

Any help/pointers would be much appreciated

symcbean · Accepted Answer · 2013-11-13 09:52:06Z

20

The 'ALTER TABLE' bit must come first, and then each part must be seperated by a comma:

ALTER TABLE gitags_items
DROP PRIMARY KEY,
ADD COLUMN id INT NOT NULL AUTO_INCREMENT FIRST,
ADD PRIMARY KEY (id,component,tag_id,item_id);

but I'm not sure if you can drop and create a primary key in the same staatement.

answered Nov 13, 2013 at 9:52

symcbean

48.4k6 gold badges63 silver badges99 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Kilasa Mj · Accepted Answer · 2015-08-19 21:20:17Z

2

This one works fine, there was the problem with the commas, theres no need to drop the primary key since your going to set one yourself

ALTER TABLE gitags_items ADD id INT NOT NULL AUTO_INCREMENT FIRST, ADD PRIMARY KEY(id,component,tag_id,item_id);

answered Aug 19, 2015 at 21:20

Kilasa Mj

212 bronze badges

Comments

Ashok Maharjan · Accepted Answer · 2013-11-13 09:29:53Z

0

First you have to make 'id' column primary key before setting autoincrement.

answered Nov 13, 2013 at 9:29

Ashok Maharjan

1631 silver badge7 bronze badges

1 Comment

symcbean Over a year ago

This was a problem back around v3 - in current versions, there's only a constraint for MyISAM tables where the autoincrement value must be the first entry in the index. "For MyISAM tables, you can specify an AUTO_INCREMENT secondary column in a multiple-column key" - from dev.mysql.com/doc/refman/5.1/en/create-table.html

Eric Aya · Accepted Answer · 2018-12-10 12:38:36Z

0

Try to add the following code to my.cnf

sql-mode="NO_ENGINE_SUBSTITUTION,ERROR_FOR_DIVISION_BY_ZERO"

then, restart MySQL

# service mysqld restart

edited Dec 10, 2018 at 12:38

Eric Aya

70.2k36 gold badges190 silver badges266 bronze badges

answered Dec 10, 2018 at 12:22

Sahin S.

514 bronze badges

Collectives™ on Stack Overflow

MySQL alter table add column with primary key syntax error

4 Answers 4

Comments

Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related