[英]How to reference two tables using hasOne with sequelize.js
考慮到sequelize-auto生成的以下3個模型:
sequelize.define('users', {
id: {
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true,
autoIncrement: true
},
first: {
type: DataTypes.STRING,
allowNull: true
},
last: {
type: DataTypes.STRING,
allowNull: true
}
}, {
tableName: 'users',
underscored: true,
timestamps: false
});
sequelize.define('groups', {
id: {
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true,
autoIncrement: true
},
parent_id: {
type: DataTypes.INTEGER,
allowNull: true,
references: {
model: 'groups',
key: 'id'
}
}
}, {
tableName: 'groups',
underscored: true,
timestamps: false
});
sequelize.define('user_groups', {
group_id: {
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true,
references: {
model: 'groups',
key: 'id'
}
},
user_id: {
type: DataTypes.INTEGER,
allowNull: false,
references: {
model: 'users',
key: 'id'
}
}
}, {
tableName: 'user_groups',
underscored: true,
timestamps: false
});
我原以為會生成hasOne語句,但是我必須像這樣指定它們:
user_groups.hasOne(orm.models.users, { foreignKey: "id" });
user_groups.hasOne(orm.models.groups, { foreignKey: "id" });
還請考慮表中的以下數據:
users (id, first, last):
1, John, Doe
group (id, parent_id):
1, NULL
2, NULL
3, NULL
4, NULL
user_groups (group_id, user_id):
1, 1
4, 1
執行此查詢:
sequelize.findAll("user_groups", {
attributes: ["*"],
raw: true,
include: [{
model: models.users,
}]
});
我得到以下結果:
[ { group_id: 4,
user_id: 1,
'user.id': null,
'user.first': null,
'user.last': null },
{ group_id: 1,
user_id: 1,
'user.id': 1,
'user.first': 'John',
'user.last': 'Doe' } ]
這清楚地表明sequelize將group_id用於user_id關系。
我如何指定一個將user_groups關系鏈接到它們各自的表的關系,以便能夠將用戶與多個組相關聯?
我也很好奇,因為該文檔不存在,模型定義中的“引用”鍵應該如何工作。
我能夠使用以下關聯獲取引用的數據:
groups.hasMany(orm.models.user_groups);
user_groups.belongsTo(orm.models.groups, {foreignKey: "group_id", as: "group"});
users.hasMany(orm.models.user_groups);
user_groups.belongsTo(orm.models.users, {foreignKey: "user_id", as: "user"});
和以下查詢:
sequelize.findAll("user_groups", {
attributes: ["*"],
raw: true,
include: [
{ model: users, foreignKey: "user_id", as: "user", attributes: ["first", "last"] }
]
});
預期結果:
[ { group_id: 4,
user_id: 1,
'user.first': 'John',
'user.last': 'Doe' },
{ group_id: 1,
user_id: 1,
'user.first': 'John',
'user.last': 'Doe' } ]
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