如何使用$ inc命令

时间:2017-05-02 04:54:29

标签: javascript node.js mongodb loops mongojs

我有这个mongo集合opponents来存储每个玩家的对手详情

{username:foo, foo:{foo1:0,foo2:0,foo3:0}} 
{username:foo1,foo1:{foo:0,foo2:0,foo3:0}}
{username:foo2,foo2:{foo:0,foo1:0,foo3:0}}//i.e player foo2 play 0 games with foo,foo1 and foo3

node.js服务器端的这个table对象:

 var table =[{name:"foo",rounds:3},{name:"foo1",rounds:3},{name:"foo2",rounds:3},{name:"foo3",rounds:3}] //all players' name in a table with their rounds number

对于桌上的每个玩家,我想追加他们的对手'相应的opponent集合的名称和轮次(当然不需要追加)。期望的结果是:

{username:foo, foo:{foo1:3,foo2:3,foo3:3}}
{username:foo1,foo1:{foo:3,foo2:3,foo3:3}}
{username:foo2,foo2:{foo:3,foo1:3:foo3:3}}
{username:foo3,foo3:{foo:3,foo1:3,foo2:3}}

我有一个自定义函数fun(name),可以为每位玩家返回一系列对手的名字。因此fun(table[0].name)会返回[foo1,foo2,foo3]

function fun(name){
  var result = [];
    for (var i = 0; i <players.length; i++){
       if(players[i].name!=name){
         result.push(players[i].name)
         }
      }
        return result;
 }

这是我目前的代码:

     for (var i =0;i<table.length;i++){
      db.opponents.update({username:table[i].name},{$inc:{[table[i].name + '.' + fun(table[i].name)[0] ] :table[i].rounds}})
      if (table.length>2){
      db.opponents.update({username:table[i].name},{$inc:{[table[i].name + '.' + fun(table[i].name)[1] ] :table[i].rounds}})
    }
     if (table.length>3){
      db.opponents.update({username:table[i].name},{$inc:{[table[i].name + '.' + fun(table[i].name)[2] ] :table[i].rounds}}) 
    }

但它是严格的硬编码,如果table.length增加,我需要更多的代码行。如何使用变量使其更紧凑?我试图使用嵌套循环,但这更糟糕。

1 个答案:

答案 0 :(得分:0)

问题解决了:

for (var i = 0; i < table.length; i++) {
   db.opponents.update({username:table[i].name},{$inc:{[table[i].name + '.' + fun(table[i].name)[0] ] :table[i].rounds}})
    for (var j = 1;j<fun(table[i].name).length;j++){
      db.opponents.update({username:table[i].name},{$inc:{[table[i].name + '.' + fun(table[i].name)[j] ] :table[i].rounds}})
     }
  }