Mongoose - 保持模型与更改相关联

Question

When I have two Schemas and they refer one another like this:

    const SchemaA = new Schema({
        _schemaB: [{
            type: Schema.Types.ObjectId,
            ref: 'SchemaA'
        }]
    });

    const SchemaB = new Schema({
        _schemaA: {
            type: Schema.Types.ObjectId,
            ref: 'SchemaB'
        }
    });

    mongoose.model('SchemaA', SchemaA);
    mongoose.model('SchemaB', SchemaB);

Every time I create a document of the type SchemaB, I need to add it to the collection of SchemaA to keep it updated.

To achieve it, I'm using a pre.save(...) hook in the SchemaB, but I was wondering if there is a better way to do it.

Thank you!

Answer 1

The only issue I see with using pre hook is what will happen if pre hook succeeds and then actual save fails. In that case you may consider using mongoose transaction to make sure data are saved as one atomic operation.

    const session = await SchemaB.startSession();
    session.startTransaction();
    try {
        // save new SchemaB
        // add to SchemA and save SchemaA

        await session.commitTransaction();
        session.endSession();

    } catch (e) {
        await session.abortTransaction();
        session.endSession();
    }