Sequelize - .update - setTags is not a function-CodePudding

"setTags is not a function"

I have Many-to-Many relationships for Posts and Tags.

db.tag.belongsToMany(db.post, {
  through: 'post_tags',
  foreignKey: 'tagId',
  otherKey: 'postId',
})
db.post.belongsToMany(db.tag, {
  through: 'post_tags',
  foreignKey: 'postId',
  otherKey: 'tagId',
})

I'm trying to update the Post's content, including the associated Tags.

This beginning at line 7:

Check for tags
Match found tags
Set the tags of post

exports.update = (req, res) => {
      const id = req.params.id
      Post.update(req.body, {
        where: { id: id },
      })
        .then((number) => {
          if (req.body.tags) {
            Tag.findAll({
              where: {
                name: {
                  [Op.or]: req.body.tags,
                },
              },
            }).then((tag_items) => {
              res.setTags(tag_items)
            })
          }
          if (number == 1) {
            res.send({
              message: 'This post attempt was successful.',
            })
          } else {
            res.send({
              message: `Problem with updating id=${id}. May not exist, or req.body could be empty!`,
            })
          }
        })
        .catch((err) => {
          res.status(500).send({
            message: 'There was an error updating post id='   id,
          })
        })
    }

I use something very similar for creating a Post.

I was hoping this would work like how it does for that.

I have read so much of the documents and online searches.

At this point I feel like it must be something simple I'm overlooking.

Maybe even a misspelling, or bad positioning of something.

I have tried creating response data with findByPk as the Post.

Then running this with setTags, I still get the same error.

Not sure if maybe because Post.update returns different data?

Than doing Post.create, I thought I read something on this.

But I had tried adding another parameter and wasn't getting expected results.

If you can offer any advice, it would be greatly appreciated.

Thank you!

CodePudding user response：

You called setTags in res which is not a Sequeize model of Post. You need to get Post instance first like this:

 Post.findOne({
        where: { id: id },
      }).then((post) => {
if (req.body.tags) {
            Tag.findAll({
              where: {
                name: {
                  [Op.or]: req.body.tags,
                },
              },
            }).then((tag_items) => {
              post.setTags(tag_items)
            })
          }  
})

And I recommend to use async/await to have straint-forward code instead of chain of then in this case:

exports.update = async (req, res) => {
      const id = req.params.id
   try {
      const number = await Post.update(req.body, {
        where: { id: id },
      })
      if (req.body.tags) {
        const post = await Post.findOne({
          where: { id: id },
        })
        const tag_items = await Tag.findAll({
           where: {
             name: {
               [Op.or]: req.body.tags,
             },
          });
          post.setTags(tag_items)
      }
      if (number == 1) {
         res.send({
           message: 'This post attempt was successful.',
         })
      } else {
         res.send({
           message: `Problem with updating id=${id}. May not exist, or req.body could be empty!`,
         })
      }
  } catch((err) {
       res.status(500).send({
         message: 'There was an error updating post id='   id,
       })
  }
}