续集：属性“播放列表”和关联“播放列表”之间的命名冲突？

Question

我正在使用node.js，Sequelize和MariaDB，并且遇到以下错误，我不确定该如何解决？

错误：在模型playlist_entry上的属性“播放列表”和关联“播放列表”之间命名冲突。要解决此问题，请更改foreignKey或更改为关联定义中的值

我的Javascript：

Entities = function (settings, context) {

    sequelize = context.sequelize;

    var entities = {

        Playlist: this.sequelize.define('playlist', {
            name: Sequelize.STRING,
            description: Sequelize.STRING
        }),     

        PlaylistEntry: this.sequelize.define('playlist_entry', {
            playlist: Sequelize.INTEGER
            //track: Sequelize.INTEGER
        })

    };  

     entities.PlaylistEntry.belongsTo(
         entities.Playlist,
         { foreignKey: { name: 'fk_playlist' }});

    return entities;                    
}

我的桌子：

CREATE TABLE `playlist` (
  `id` int(11) unsigned NOT NULL,
  `name` varchar(255) NOT NULL,
  `description` varchar(255) DEFAULT NULL,
  `createdAt` timestamp NULL DEFAULT NULL,
  `updatedAt` timestamp NULL DEFAULT NULL,
  `external_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `playlist_entry` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `playlist` int(11) unsigned DEFAULT NULL,
  `track` int(11) unsigned DEFAULT NULL,
  `createdAt` timestamp NULL DEFAULT NULL,
  `updatedat` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `track_idx` (`track`),
  KEY `playlist_idx` (`playlist`),
  CONSTRAINT `fk_playlist` FOREIGN KEY (`playlist`) REFERENCES `playlist` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

Answer 1

I faced exactly this problem while play with Sequelize, It's happened because the column name and reference name are same

Wrong Implementation

module.exports = (sequelize, DataTypes) => {
  const session = sequelize.define('session', {
    menteeId: DataTypes.INTEGER,
  }, {});

  session.associate = (models) => {
    session.belongsTo(models.user, {
      foreignKey: 'menteeId',
      as: 'menteeId',
      onDelete: 'CASCADE',
    });
  };
  return session;
};

Here the column name (menteeId) and alias name (menteeId) are the same, To resolve this you just need to change alias name

Correct Implementation

module.exports = (sequelize, DataTypes) => {
  const session = sequelize.define('session', {
    menteeId: DataTypes.INTEGER,
  }, {});

  session.associate = (models) => {
    session.belongsTo(models.user, {
      foreignKey: 'menteeId',
      as: 'MenteeId', // Changes applied here
      onDelete: 'CASCADE',
    });
  };
  return session;
};

In your case, you can do this

entities.PlaylistEntry.belongsTo(
    entities.Playlist,
    { 
    foreignKey: { name: 'fk_playlist' },
    as: 'PlayListAlias', // Appropriate name
    },
);