用Mongoose以编程方式构建动态查询

尝试创建

query

//generate query object based on availability of value var query = {};if( your_variable !== "" ) {    query["some_key"] = your_variable;}if( your_second_variable !== "" ) {    query["some_other_key"] = your_second_variable;}mongoose.model('customers').find(query, function(err, c) {    //do something});