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  • mongoose 创建自增字段方法

    first: create counter collection in mongodb:
    > db.counters.insert({_id:"entityId",seq:0})
    WriteResult({ "nInserted" : 1 })


    then put below in a model.js:

    var CounterSchema = Schema({
    _id: {type: String, required: true},
    seq: { type: Number, default: 0 }
    });
    var counter = mongoose.model('counter', CounterSchema);

    var entitySchema = mongoose.Schema({
    testvalue: {type: String}
    });

    entitySchema.pre('save', function(next) {
    var doc = this;
    counter.findByIdAndUpdate({_id: 'entityId'}, {$inc: { seq: 1} }, function(error, counter) {
    if(error)
    return next(error);
    doc.testvalue = counter.seq;
    next();
    });
    });

    借鉴: http://stackoverflow.com/questions/28357965/mongoose-auto-increment

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  • 原文地址:https://www.cnblogs.com/IamThat/p/5668411.html
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