mongodb - 多参数mongodb查询

Question

找出成本最低、评分最高、平均评分最高的项目。这是正确的方法吗？

exports.getBestEconomicalProject = function(number, callback){  
    var result = ProjectModel.find().sort({averageCost: 1}, {ratingCount : -1}, {averageRating : -1}).select({_id: 1}).limit(number).exec(
            function(err, projects) {
                callback(null, projects)
            }
        );  
    return result;
}

Answer 1

您需要将所有sort术语组合成一个对象：

exports.getBestEconomicalProject = function(number, callback){  
    var result = ProjectModel.find()
        .sort({averageCost: 1, ratingCount : -1, averageRating : -1})
        .select({_id: 1})
        .limit(number)
        .exec(
            function(err, projects) {
                callback(null, projects)
            }
        );  
    return result;
}

或者使用字符串格式sort：

exports.getBestEconomicalProject = function(number, callback){  
    var result = ProjectModel.find()
        .sort('averageCost -ratingCount -averageRating')
        .select({_id: 1})
        .limit(number)
        .exec(
            function(err, projects) {
                callback(null, projects)
            }
        );  
    return result;
}