Easy way to increment Mongoose document versions f

问题:

I want to start taking advantage of Mongooses document versioning (__v key). I was having an issue actually incrementing the version value, then I found that you have to add this.increment() when executing a query.

Is there a way to have automatically incremented? For now, I just added it to the pre middleware for a update-type queries:

module.exports = Mongoose => {
    const Schema = Mongoose.Schema

    const modelSchema = new Schema( {
        name: Schema.Types.String,
        description: Schema.Types.String
    } )

    // Any middleware that needs to be fired off for any/all update-type queries
    _.forEach( [ 'save', 'update', 'findOneAndUpdate' ], query => {
        // Increment the Mongoose (__v)ersion for any updates
        modelSchema.pre( query, function( next ) {
            this.increment()
            next()
        } )
    } )
}

Which seems to work.. But I kinda thought there would already be a way to do this within Mongoose.. am I wrong?

回答1:

I'd say this is the way to go. pre middleware fits exactly this need, and I don't know any other way. In fact this is what I'm doing in all my schemas.

What you need to be aware of though, is the difference between document and query middleware. Document middleware are executed for init, validate, save and remove operations. There, this refers to the document:

schema.pre('save', function(next) {
  this.increment();
  return next();
});

Query middleware are executed for count, find, findOne, findOneAndRemove, findOneAndUpdate and update operations. There, this refers to the query object. Updating the version field for such operations would look like this:

schema.pre('update', function( next ) {
  this.update({}, { $inc: { __v: 1 } }, next );
});

Source: mongoose documentation.

回答2:

For me the simplest way to do that is :

clientsController.putClient = async (req, res) => {

const id = req.params.id;
const data = req.body;
data.__v++;

await Clients.findOneAndUpdate({ _id: id }, data)
    .then( () => 
    {
        res.json(Ok);
    }
    ).catch ( err => {
        Error.code = '';
        Error.error = err;
        res.json(Error);
    })

};