问题
I have a database with the following tables:
CREATE TABLE IF NOT EXISTS `app_user` (
  `user_id` INT NOT NULL,
  `user_name` VARCHAR(45) NOT NULL,
  PRIMARY KEY (`user_id`))
ENGINE = InnoDB;
CREATE TABLE IF NOT EXISTS `user_folder` (
  `user_id` INT NOT NULL,
  `document_id` INT NOT NULL,
  PRIMARY KEY (`user_id`, `document_id`),
  CONSTRAINT `fk_user_document_user`
    FOREIGN KEY (`user_id`)
    REFERENCES `zinc`.`app_user` (`user_id`)
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB;
CREATE TABLE IF NOT EXISTS `folder_content` (
  `user_id` INT NOT NULL,
  `document_id` INT NOT NULL,
  `content_id` INT NOT NULL,
  PRIMARY KEY (`user_id`, `document_id`, `content_id`),
  CONSTRAINT `fk_folder_content_folder`
    FOREIGN KEY (`user_id` , `document_id`)
    REFERENCES `zinc`.`user_folder` (`user_id` , `document_id`)
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB;
I need to create a Sequelize model to represent it. The only problem I have is with the relation folder_content and user_folder because of the composite key.
How can I create this sequelize model?
This is what I have so far:
var AppUser = sequelize.define('app_user', 
{userId: {type: Sequelize.INTEGER, primaryKey: true, field: 'user_id'}, ... } );
var UserFolder = sequelize.define('user_folder', 
{userId: {type: Sequelize.INTEGER, primaryKey: true, field: 'user_id'}, 
documentId: {type: Sequelize.INTEGER, primaryKey: true, field: 'document_id'}... });
var FolderContent = sequelize.define('folder_content', {
userId: {type: Sequelize.INTEGER, primaryKey: true, field: 'user_id'}, 
documentId: {type: Sequelize.INTEGER, primaryKey: true, field: 'document_id'}, 
contentId: {type: Sequelize.INTEGER, primaryKey: true, field: 'content_id'}... });
UserFolder.hasMany(FolderContent);
FolderContent.belongsTo(UserFolder, {foreingKey: !! });// <- PROBLEM
回答1:
Now Sequelize doesn't support composite foreign keys. This creates several problems.
- When Sequelize creates a table, the table definition does not have a composite FK.
 To solve this problem I use theafterSynchook on the model and a function that adds a FK to the table if it does not exist. Example code.
- When I use the findAllmethod withincludesuch model, I use theinclude[].onoption of thefindAllmethod. Or if you don't use as many joins as I do, you can usescopewhen creating an association (see).
来源:https://stackoverflow.com/questions/29015156/sequelize-composite-foreign-key