Error appears in sql when trying to add multiple foreign keys

Question

I am trying to create an index and multiple foreign keys in mysql but when I Include the code below:

CREATE INDEX par_ind on Image_Question (SessionId,Questi         


        

Answer 1

here i have sorted out your problem and worked fine for me

ALTER TABLE `question`     CHANGE `QuestionId` `QuestionId` INT(11) NOT NULL,    ADD PRIMARY KEY(`QuestionId`);

first i have changed the QuestionId to primary key

ALTER TABLE `image_question` ADD INDEX `questionId` (`QuestionId`);

then added the index on QuestionId of image_question

ALTER TABLE  `question` ADD CONSTRAINT `FK_question` FOREIGN KEY (`QuestionId`)
REFERENCES `image_question` (`QuestionId`) ON DELETE NO ACTION ;

and then first relationship for QuestionId works successfully

ALTER TABLE `question`     CHANGE `SessionId` `SessionId` INT(11) NOT NULL;
ALTER TABLE `image_question`     CHANGE `SessionId` `SessionId` INT(11) NOT NULL;

then changed the data type of SessionId of both tables to int

ALTER TABLE `image_question` ADD INDEX `NewIndex1` (`SessionId`);

then added index on SessionId of image_question

ALTER TABLE `image_question` ADD CONSTRAINT `FK_image_question` FOREIGN KEY (`SessionId`) REFERENCES `question` (`SessionId`) ON DELETE NO ACTION ;

and here is your second relationship for SessionId hope it works fine for you also