belongsToMany 與 Sequelize 關聯的限制

Question

我想知道，如何限制我的 belongsToMany 關系。 我嘗試添加限制，但出現此錯誤：

"message": "只有 HasMany 關聯支持 include.separate",

我有 2 個表：

| peoples (id, code) 
| people-friends (fk_user_id, fk_friend_id) // fk_friend_id is an id from user

我的請求：

    await db.People.findAll({
    where: {
    id: parent.dataValues.id,
    },
    include: [
    {
        model: db.People,
        as: "Friends",
        limit: 2, // <--- LIMIT
    },
    ],
})

人 model：

People.associate = (models) => {
    // People relations
    models.People.belongsToMany(models.People, {
        as: "Friends",
        through: models.PeopleFriend,
        foreignKey: "fk_user_id",
        otherKey: "fk_friend_id",
    })
}

Answer 1

如果你希望某個用戶的朋友限制為 2 個朋友（哪些？你必須添加一個order選項）你可以像這樣查詢 PeopleFriend 包括 People model：

await db.PeopleFriend.findAll({
    where: {
      fk_user_id: parent.dataValues.id
    },
    limit: 2, // <--- LIMIT
    order: [['Friend', 'name', 'asc']],
    include: [
    {
        model: db.People,
        as: "Friend",
    },
    {
        model: db.People,
        as: "User",
    },
    ],
})

不要忘記將來自 PeopleFriend 的關聯添加到兩個 People 鏈接。