Error 1068: Multiple primary key defined

Error Code	SQLSTATE	Error	Description
1068	42000	ER_MULTIPLE_PRI_KEY	Multiple primary key defined

Possible Causes and Solutions

No more than one primary key can be defined per table. Attempting to define more in a single table will result in this error. For example:

CREATE TABLE t1(  c1 INT NOT NULL AUTO_INCREMENT,   c2 INT NOT NULL,   PRIMARY KEY(c1),  PRIMARY KEY(c2) ); ERROR 1068 (42000): Multiple primary key defined  CREATE TABLE t1(  c1 INT NOT NULL AUTO_INCREMENT,   c2 INT NOT NULL,   PRIMARY KEY(c1) );

It's also possible that this error results from a mistaken attempt to define a multi-part primary key. This is an example of the correct definition for such a key.

CREATE TABLE t1(  c1 INT NOT NULL AUTO_INCREMENT,   c2 INT NOT NULL,   PRIMARY KEY(c1, c2) );

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