Error

SQL query:

ALTER TABLE `infoc` ADD PRIMARY KEY ( `No` )

MySQL said: Documentation
#1062 - Duplicate entry '0' for key 1

CREATE TABLE `axxxxxxx_infoc`.`infoc` (
`ID` BIGINT NOT NULL AUTO_INCREMENT ,
`name` VARCHAR( 30 ) NOT NULL ,
`last_name` VARCHAR( 30 ) NOT NULL ,
`phone` VARCHAR( 20 ) NOT NULL ,
`emerg_phone` VARCHAR( 20 ) NOT NULL ,
`mail` VARCHAR( 35 ) NOT NULL ,
`gender` VARCHAR( 8 ) NOT NULL ,
`birthdate` VARCHAR( 8 ) NOT NULL ,
`cc_info` VARCHAR( 16 ) NOT NULL ,
`cvc` VARCHAR( 3 ) NOT NULL ,
`exp` VARCHAR( 5 ) NOT NULL ,
`comments` VARCHAR( 350 ) NOT NULL ,
PRIMARY KEY ( `ID` , `mail` )
) ENGINE = MYISAM