使用MongoDB在$中传递一个参数

I've a little problem with my script. I cannot passing a parameter (MYPARAMETER in the example) in the function in the '$where'.

我的剧本有点问题。我不能在“$where”函数中传递一个参数(本例中的MYPARAMETER)。

You have an idea for help me ? Thanks.

你有什么办法帮我?谢谢。

var MYPARAMETER = "dqsd qsdqs &é&é";

MyCol.findOne({

    $where: function(MYPARAMETER) 
    { 
        var tab1="ÀÁÂÃÄÅàáâãäåÒÓÔÕÖØòóôõöøÈÉÊËèéêëÇçÌÍÎÏìíîïÙÚÛÜùúûüÿÑñ!#$€%&'`(),;:/@.*[]\|";
        var tab2=   "aaaaaaaaaaaaooooooooooooeeeeeeeecciiiiiiiiuuuuuuuuynn                      ";
        rep2=tab1.split('');
        rep=tab2.split('');
        parray=new Array();
        var i=-1;
        while(rep2[++i])
        {
            parray[rep2[i]]=rep[i]
        }
        var chaine = this.name.replace(/\s{1,}/g,"-");
        chaine = chaine.replace(/./g, function($0){return (parray[$0])?parray[$0]:$0 });
        chaine = chaine.replace(/\s/g,"");


        return (chaine == MYPARAMETER);
    }
},

3 个解决方案

#1

A $where executes on the server, and thus wouldn't have access to a variable that was locally declared on another server. JavaScript should be used as a last resort generally in MongoDB, and this appears to go the other way and perform a LOT of very time consuming work.

在服务器上执行的$，因此不能访问在另一台服务器上声明的变量。在MongoDB中，JavaScript应该作为最后的解决方案，而这似乎恰恰相反，它执行了大量耗时的工作。

You'd need to build the function as a string and include the value directly.

您需要将函数构建为一个字符串，并直接包含该值。

#2

To use variables in $where query, first create mongo query as a string and then parse string to JSON when passing as parameter

要在$where查询中使用变量，首先创建mongo查询作为字符串，然后在传递参数时解析字符串到JSON。

Example:

例子:

var query = '{"$where": "function() { return (\'' + address + '\').indexOf(this.city) >= 0 }"}';
db.city.find(JSON.parse(query);

#3

This one is works for me , Just try to store a query as a string in one variable then concat your variable in query string,

这个对我来说是可行的，只要将查询作为字符串存储在一个变量中然后将变量concat保存在查询字符串中，

var local_var = 42

var local_var = 42

var query = "{$where: function() { return this.a == "+local_var+"}}"

var查询= "{$where: function(){返回这个。一个= = + local_var + } }”

db.test.find(query)

db.test.find(查询)

watch the reference exaple

看参考的做法

#1