组合复合外键 [英] Sequelize Composite Foreign Key

问题描述

我有一个包含以下表格的数据库:

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;

我需要创建一个Sequelize模型来表示它.由于组合键，我唯一的问题是与folder_content和user_folder之间的关系.

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.

如何创建这个续集模型?

How can I create this sequelize model?

这是我到目前为止所拥有的:

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

推荐答案

现在，Sequelize不支持复合外键.这会带来一些问题.

Now Sequelize doesn't support composite foreign keys. This creates several problems.

1. 当Sequelize创建表时，表定义没有复合FK.
   为了解决这个问题，我在模型和函数上使用了afterSync钩子 如果表中不存在FK，则会将其添加到表中. 示例代码.
2. 当我将findAll方法用于include这样的模型时，我使用findAll方法的include[].on选项.或者，如果您不使用我那么多的联接，则可以在创建关联时使用scope(请参阅).

1. When Sequelize creates a table, the table definition does not have a composite FK.
   To solve this problem I use the afterSync hook on the model and a function that adds a FK to the table if it does not exist. Example code.
2. When I use the findAll method with include such model, I use the include[].on option of the findAll method. Or if you don't use as many joins as I do, you can use scope when creating an association (see).

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