更新Mongodb中的嵌入式阵列值

Posted 2021-04-17

我在Mongo DB Collection中有以下内容

我需要能够将阿森纳的积分更新为等于巴塞罗那的积分。我见过的任何视频教程似乎都没有提供这样的基本功能。

我认为在Mongodb中这是可能的吗？

db.teams.insert({
    team_id: "spa1",
    date_founded: new Date("Oct 04, 1912"),
     league: "La Liga",
     points: 80,
     name: "Barcelona",
     players: [ { p_id: "Messi", goal: 195, caps: 189, age: 30 },
              { p_id: "Valdes", goal: 0, caps: 158, age: 27 },
              { p_id: "Iniesta", goal: 72, caps: 25, age: 31},
              { p_id: "Pique", goal: 9, caps: 201, age: 38 } ]
     });



db.teams.insert({
    team_id: "eng2",
    date_founded: new Date("Oct 04, 1899"),
     league: "Premier League",
     points: 52,
     name: "Arsenal",
     players: [ { p_id: "Mata", goal: 5, caps: 24, age: 27 },
              { p_id: "Bergkamp", goal: 95, caps: 98, age: 48 } ]
     });

答案

您可以使用两个单独的查询执行此操作：

// find the barcelona document first
var cursor = db.teams.find({team_id: "spa1"});
var barcelona = cursor.next();
// set the arsenal points equal to barcelona ones
db.teams.update({team_id: "eng2"}, {$set: {"points": barcelona.points}});