MySQL: errorno 121

I'm getting this error in MySQL create. I'm doing:

CREATE TABLE `blogReply` (

    `Id`      INT(24)      NOT NULL AUTO_INCREMENT COMMENT 'Primary Key of This Table',
    `blogId`  INT(24)      NOT NULL COMMENT 'Blog where this reply was posted',
    `userId`  INT(24)      NULL COMMENT 'User the blog was posted by',
    `name`    VARCHAR(100) NULL DEFAULT 'Unknown' COMMENT 'The Name of the user that the reply was posted by',
    `email`   VARCHAR(100) NULL DEFAULT 'Unknown' COMMENT 'The Email of the user that the reply was posted by',
    `http`    VARCHAR(300) NULL DEFAULT 'Unknown' COMMENT 'The Webaddress of the user that the reply was posted by',
    `message` TEXT         NOT NULL COMMENT 'text of the blog',
    `votes`   INT(10)      DEFAULT 0 COMMENT 'Rating of the Blog',
    `ratedBy` TEXT         COMMENT 'People who have already Voted on this blog',
    `dateReg` BIGINT       NOT NULL COMMENT 'Date the User was Registered',

    PRIMARY KEY (`Id`),

    CONSTRAINT `FK_userId` FOREIGN KEY(`userId`)
        REFERENCES `user` (`Id`)
        ON DELETE SET NULL
        ON UPDATE CASCADE,

    CONSTRAINT `FK_blogId` FOREIGN KEY(`blogId`)
        REFERENCES `blog` (`Id`)
        ON DELETE CASCADE
        ON UPDATE CASCADE

) ENGINE = InnoDB;

Any Ideas? The Error States: Can't create table './xxxxxxxx/blogReply.frm' (errno: 121)

 Answers

Check that all your constraints are really spelled out correctly, also check that there's not any other tables that uses the constraint names FK_userId or FK_blogId

---

please check that your foreign key which you are creating is same in all aspects such as datatype with the referred table column . Each foreign key name should be unique for those tables in which it is created , it should not be used in anyother tables. for the above problem the Foreign key name "FK_userId" should not be used in any other table .