更新MongoDB shell中的查询

Question

在shell中,我的查询是:

db.checkin_4e95ae0926abe9ad28000001.update({location_city:"New York"}, {location_country: "FUDGE!"});

但是,它实际上并没有更新我的记录.它也没有错误.当我执行db.checkin_4e95ae0926abe9ad28000001.find({location_city:"New York"});此操作后,我得到了所有结果,但location_country没有改变:

{
    "_id": ObjectId("4e970209a0290b70660009e9"),
    "addedOn": ISODate("2011-10-13T15:21:45.772Z"),
    "location_address1": "",
    "location_city": "New York",
    "location_country": "United States",
    "location_latLong": {
        "xLon": -74.007124,
        "yLat": 40.71455
    },
    "location_source": "socialprofile",
    "location_state": "New York",
    "location_zip": ""
}

Answer 1

这是因为在更新函数的第二个参数中,您需要使用$ set运算符进行更新location_country,如下例所示:

db.checkin_4e95ae0926abe9ad28000001.update(
   {location_city:"New York"}, //find criteria
   // this row contains fix with $set oper
   { $set : { location_country: "FUDGE!"}}); 

在这里,您可以找到可用更新运算符的列表.

Answer 2

db.m_country.update(
    {"countryId": "962a0935-bf3d-4f63-a53c-254760273ede"}, 
    {$set: {'countryPopulation': '12540000'}})

Answer 3

版本3.6中已更改.以下是更新的语法:

db.collection.update(
   <query>,
   <update>,
   {
     upsert: <boolean>,
     multi: <boolean>,
     writeConcern: <document>,
     collation: <document>,
     arrayFilters: [ <filterdocument1>, ... ]
   }
)

示例:

db.getCollection('products').update({},{$unset: {translate:1, qordoba_translation_version:1}}, {multi: true})

在你的例子中:

db.checkin_4e95ae0926abe9ad28000001.update(
   {location_city:"New York"}, //query
   // $update query
   { $set : { location_country: "FUDGE!"}});

默认情况下,update()方法更新单个文档.设置多参数以更新符合查询条件的所有文档.

例2:

   db.checkin_4e95ae0926abe9ad28000001.update(
       {location_city:"New York"}, //query
       // $update query
       { $set : { location_country: "FUDGE!"}}, {multi: true});