Question

When I try to alter a table I got this error:

#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 (id)’ at line 1

Here is my query:

ALTER TABLE gk
ADD COLUMN id MEDIUMINT NOT NULL AUTO_INCREMENT,  PRIMARY KEY (id);

How can I resolve this?

Answer 1

In an ALTER TABLE statement, a single ADD specification can’t add both a column and a constraint; you’ll need to put them in separate specifications:

ALTER TABLE gk ADD COLUMN id MEDIUMINT NOT NULL AUTO_INCREMENT,
               ADD PRIMARY KEY (id);

(See §13.1.6 “ALTER TABLE Syntax” in the MySQL 5.6 Reference Manual.)