Mysql can't create table errno 121

Question

Why am I getting this error? I don't have any foreign keys

drop table if exists t_issue;
SET foreign_key_checks = 0;SET storage_engine=INNODB;
CREATE TABLE `t_issue` (
`id_issue` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
`fk_project` int(11) DEFAULT NULL,
`subject` varchar(255) DEFAULT NULL,
`estimated_due_date` date DEFAULT NULL,
`due_date` date DEFAULT NULL,
`done_ratio` int(11) DEFAULT NULL,
`fk_status` int(11) DEFAULT NULL,
`fk_assigned_to` int(11) DEFAULT NULL,
`fk_owner` int(11) DEFAULT NULL
) ENGINE=innodb DEFAULT CHARSET=latin1

• Malcolm: Seems to work OK for me.
• Nagaraj S: It's working.What error you are facing
• luca.p.alexandru: I changed the name of the table to t_issue1 and the query works for that, for t_issue it doesen't. However I did a "Show tables" but no table named t_issue exists. What could the problem be?
• Nagaraj S: @patentul check here sqlfiddle.com/#!2/3d392/1
• Ravinder Reddy: It is the same previous question from you: Mysql can't create table errno 121

Answer 1

Mysql can't create table errno 121

You will get this message if you are trying to add a constraint with a name that is already used somewhere else.

To check constraints, use the following SQL query:

SELECT
 constraint_name,
 table_name
FROM
 information_schema.table_constraints
WHERE
 constraint_type = 'FOREIGN KEY'
AND table_schema = DATABASE()
ORDER BY
 constraint_name;

Reference: https://dba.stackexchange.com/questions/425/error-creating-foreign-key-from-mysql-workbench

See also: SQL - error code 1005 with error number 121

• luca.p.alexandru: I did this, none of the constraints resulted in the query are being used in my current query for generating this table
• luca.p.alexandru: yes I did, One constraint indeed was being used, I replaced that, but it still does not work
• luca.p.alexandru: Error Code: 1005. Can't create table 'ticket_tool.t_issue' (errno: 121)
• luca.p.alexandru: Well I did try again, but without success, as I said I replaced the constraints that are used
• jmail: (+1) for useful question, because Most of the person(stack over flowers) don't know this question, so, get the +1 for the useful question...