sequelize findAll 不检查当前用户是否喜欢帖子

Question

我有一个场景，如果你喜欢一个帖子，它会改变liked:false 到 liked:true这个喜欢是基于当前用户是否喜欢该帖子。问题是当新用户注册时，liked尽管新用户不喜欢该帖子，它仍然会显示为真。我如何能够检查当前用户是否喜欢该帖子？就检查当前用户是否喜欢该帖子而言，我认为我的逻辑有点不对。我想保留findAll功能，我应该获得所有帖子，而不仅仅是当前用户。有点像 instagram 或 facebook。这是帖子数组这就是我喜欢帖子的方式喜欢帖子likePost: async (req: any, res: Response) => {    const created = await models.Likes.findOne({      where: {        userId: req.session.user.id,        resourceId: req.params.id      }    });    console.log(created);    const post = await models.Post.findOne({ where: { id: req.params.id } });    // if like not created then do this    if (!created && post) {      await models.Likes.create({        userId: req.session.user.id,        resourceId: req.params.id      }).then(() => {        post.increment("likeCounts", { by: 1 });        post.update({ liked: req.session.user.id ? true : false });        res.status(200).send({          message: "You liked this post"        });      });      // else if post does not exist    } else if (!post) {      res.status(200).send({        message: "there is not post to be liked"      });    } else {      // else if a like does exist destroy like      await models.Likes.destroy({        where: {          userId: req.session.user.id        }      }).then(() => {        post.decrement("likeCounts", { by: 1 });        res.status(200).send({          message: "You unliked this post"        });      });    }这就是我获取帖子的方式。

Answer 1

因此，通过遵循 @doublesharp 帮助，我能够通过使用续集数据类型VIRTUAL以及使用getDataValue来确定当前用户是否喜欢该帖子

更新代码

岗位(模型)

"use strict";

module.exports = (sequelize, DataTypes) => {

    var Post = sequelize.define("Post", {

        title: DataTypes.STRING,

        postContent: DataTypes.STRING,

        liked: {

            type: DataTypes.VIRTUAL,

            allowNull: false,

            defaultValue: false,

            get: function () {

                return this.getDataValue('Likes').length ? true : false;

            }

        },

        likeCounts: {

            type: DataTypes.INTEGER,

            allowNull: false,

            defaultValue: 0,

            validate: {

                min: 0,

            }

        },

        authorId: DataTypes.INTEGER

    }, {});

    Post.associate = function (models) {

        Post.belongsTo(models.User, {

            as: "author",

            foreignKey: "authorId",

            onDelete: "CASCADE"

        });

        Post.hasMany(models.Likes, {

            foreignKey: "resourceId",

            timestamps: false,

            targetKey: "id",

            onDelete: "CASCADE"

        });

    };

    return Post;

};

//# sourceMappingURL=post.js.map

Answer 2

我相信您看到的错误是因为您没有解决由以下人员返回的承诺：

    post.increment("likeCounts", { by: 1 });

    post.update({ liked: req.session.user.id ? true : false });

这意味着将在这些查询执行之前发送响应。该post.liked值将user.id在会话中的任何时候设置为 true 。如果稍后的查询失败，您可能需要考虑使用事务来回滚一些较早的查询。我还建议使用Promise.all()进行并发查询（它会更快）并且只使用async/await不混入thenables.

likePost: async (req: any, res: Response) => {

  // fetch created and post at the same time

  const [ created, post ] = await Promise.all([

    models.Likes.findOne({

      where: {

        userId: req.session.user.id,

        resourceId: req.params.id

      }

    }),

    models.Post.findOne({

      where: {   

        id: req.params.id

      }

    }),

  ]);

  // no post, no updates

  if (!post) {

    return res.status(200).send({

      message: "there is no post to be liked"

    });

  }

  // we are going to make updates, so use a transaction, you will need to reference sequelize

  let transaction;

  try {

    transaction = await sequelize.transaction();

    if (!created && post) {

      // use Promise.all() for concurrency

      await Promise.all([

        models.Likes.create({

          userId: req.session.user.id,

          resourceId: req.params.id

        }, { transaction }),

        post.increment("likeCounts", { by: 1, transaction }),

        post.update({ liked: req.session.user.id ? true : false }, { transaction }),

      ]);

      await transaction.commit();

      return res.status(200).send({

        message: "You liked this post"

      });

    }

    await Promise.all([

      models.Likes.destroy({

        where: {

          userId: req.session.user.id

        }

      }, { transaction }),

      post.decrement("likeCounts", { by: 1, transaction }),

    ]);

    await transaction.commit();

    return res.status(200).send({

      message: "You unliked this post"

    });

  } catch (err) {

    if (transaction) {

      await transaction.rollback();

    }

    console.log('There was an error', err);

    return res.status(500);

  }

}

仅Likes在 getPost() 上返回当前用户

getPosts: async (req: any, res: Response) => {

  const posts = await models.Post.findAll({

    include: [

      { model: models.User, as: "author", attributes: ["username"] },

      // limit the likes based on the logged in user

      { model: models.Likes, required: false,

        where: { userId: req.session.user.id },

      },

    ],

    order: [["createdAt", "DESC"]],

    limit: 6

  });

  return res.json(posts);

},