sequelize mysql 中的嵌套查询以获得赞成票和反对票计数

Question

我正在尝试为 Post 投票，其中有 Answer table 关联和将投票table与回答

分开

const posts = await Posts.findAll({
    include: [{
        model: Answers,
        include: [{
          attributes: { 
              include: [[Sequelize.fn("COUNT", Sequelize.col("id")), "votesCount"]] 
          },
          model: Votes, attributes: []
        }]
    }]
});

这是我的投票架构

const Votes = sequelize.define('votes', {
    id:{
        type:Sequelize.INTEGER,
        autoIncrement:true,
        allowNull:false,
        primaryKey:true
      },
      answerId: {
        type: Sequelize.INTEGER,
        allowNull:false,
         references: {
          model: 'answers',
          key: 'id'
        }
      },
      userId: {
        type: Sequelize.INTEGER,
        allowNull:false,
         references: {
          model: 'users',
          key: 'id'
        }
      },
      voteType: { type: Sequelize.BOOLEAN, allowNull:false },
      createdAt: Sequelize.DATE,
      updatedAt: Sequelize.DATE
})

voteType true 表示赞成票，false 表示反对票

有什么方法可以用 Sequelize 得到结果吗？

期待这样的事情，

[{
            "id": 1,
            "userId": 15,
            "title": "The standard Lorem Ipsum passage, used since the 1500s",
            "description": "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor i",
            "answers": [
                {
                    "id": 1,
                    "postId": 1,
                    "userId": 33,
                    "ans": "Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia",
                }
            ],
            votes: {
                upVote: 5,
                downVote: 1
            }
        },]

Answer 1

您可以尝试使用 Sequelize.literal 通过使用子查询来获取两个计数：

const posts = await Posts.findAll({
    include: [{
        model: Answers,
        include: [{
          attributes: { 
              include: [
  [Sequelize.literal("(SELECT COUNT(*) FROM Votes WHERE answerId=answer.id AND Votes.voteType=true)"), "upVote"],
  [Sequelize.literal("(SELECT COUNT(*) FROM Votes WHERE answerId=answer.id AND Votes.voteType=false)"), "downVote"]
          ] 
          }
        }]
    }]
});

sequelize mysql 中的嵌套查询以获得赞成票和反对票计数

nested query in sequelize mysql to get upvote and downvote count

mysql

node.js

express

sequelize.js