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  MongoDB 更新文档

  • 更新文档

    MongoDB的update()和save()方法用于将文档更新为集合。update()方法更新现有文档中的值，而save()方法将现有文档替换为save()方法中传递的文档。

  • update()方法

    update()方法更新现有文档中的值。
    语法 
     
>db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)
    示例
    考虑到mycol集合具有以下数据。 
     
{ "_id" : ObjectId("5f4871eb69ad8645590791a2"), "title" : "MongoDB Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a3"), "title" : "NoSQL Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a4"), "title" : "Tutorials Point Overview" }
    以下示例将为标题为“MongoDB Overview”的文档设置新标题“New MongoDB Tutorial”。 
     
 db.mycol.find();  # 查询现有数据
{ "_id" : ObjectId("5f4871eb69ad8645590791a2"), "title" : "MongoDB Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a3"), "title" : "NoSQL Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a4"), "title" : "Tutorials Point Overview" }
> db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}}) # 修改
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })  #修改返回
> db.mycol.find(); #查询修改后的数据
{ "_id" : ObjectId("5f4871eb69ad8645590791a2"), "title" : "New MongoDB Tutorial" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a3"), "title" : "NoSQL Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a4"), "title" : "Tutorials Point Overview" }
    默认情况下，MongoDB仅更新一个文档。要更新多个文档，您需要将参数“multi”设置为true。- 
     
 db.mycol.update({'title':'MongoDB Overview'},{$set:{'title':'New MongoDB Tutorial'}},{multi:true})

  • save() 方法

    save()方法通过了新的文件替换现有的文档(带_id参数且存在该记录，如果不存在则插入一条新的)。
    语法 
     
>db.COLLECTION_NAME.save({_id:ObjectId(),NEW_DATA})
    以下示例从名为mycol的集合中检索所有文档，并以易于阅读的格式排列它们。 
     
> db.mycol.find() # 现有数据
{ "_id" : ObjectId("5f4871eb69ad8645590791a2"), "title" : "New MongoDB Tutorial" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a3"), "title" : "NoSQL Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a4"), "title" : "Tutorials Point Overview" }
> db.mycol.save( { "_id" : ObjectId("5f4871eb69ad8645590791a2"),  "title":"Tutorials Point New Topic Good  good", "by":"菜鸟教程" } );  # save 替换_id 为 5f4871eb69ad8645590791a2的文档
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })  # save 执行返回
> db.mycol.find() #查询修改后的数据
{ "_id" : ObjectId("5f4871eb69ad8645590791a2"), "title" : "Tutorials Point New Topic Good  good", "by" : "菜鸟教程" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a3"), "title" : "NoSQL Overview" }
{ "_id" : ObjectId("5f4871eb69ad8645590791a4"), "title" : "Tutorials Point Overview" }

  • findOneAndUpdate() 方法

    findOneAndUpdate() 方法中的现有文档中更新的值。
    语法： 
    
>db.COLLECTION_NAME.findOneAndUpdate(SELECTIOIN_CRITERIA, UPDATED_DATA)
    假设我们创建了一个名为empDetails的集合，并在其中插入了三个文档，如下所示- 
     
db.empDetails.insertMany(
  [
    {
      title: "Java 教程",
      author: "张三", 
      phone: "18812454545"
    },
    {
      title: "PHP 教程",
      author: "李四", 
      phone: "18912454545"
    },
    {
      title: "Python 教程",
      author: "王五", 
      phone: "19912454545"
    }
  ]
)
    以下示例更新author为“李四”的文档的phone值。 
     
db.empDetails.find(); #修改前
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "18812454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "18912454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19912454545" }
> db.empDetails.findOneAndUpdate( {author: '李四'}, { $set: {phone:"13888888888"}} );  # 修改
{
  "_id" : ObjectId("5f48781a17adfc074ccae0e8"),
  "title" : "PHP 教程",
  "author" : "李四",
  "phone" : "18912454545"
}
> db.empDetails.find(); # 查询修改后的
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "18812454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "13888888888" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19912454545" }

  • MongoDB updateOne() 方法

    此方法更新与给定过滤器匹配的单个文档。
    语法： 
    
db.COLLECTION_NAME.updateOne(<filter>, <update>)

     
db.empDetails.find(); #修改前
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "18812454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "13888888888" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19912454545" }
> db.empDetails.updateOne({author: '王五'},{ $set: { phone: '19999999999'}})  #修改
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.empDetails.find();  # 修改后
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "18812454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "13888888888" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19999999999" }

  • updateMany()方法

    updateMany() 方法更新与给定过滤器匹配的所有文档。 
     
>db.COLLECTION_NAME.update(<filter>, <update>)
    示例： 
     
db.empDetails.find();
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "18812454545" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "13888888888" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19999999999" }
> db.empDetails.updateMany({ $or:[{author:"张三"}, { author:"李四"}] } ,{ $set: { phone: '10086'}});
{ "acknowledged" : true, "matchedCount" : 2, "modifiedCount" : 2 }
> db.empDetails.find();
{ "_id" : ObjectId("5f48781a17adfc074ccae0e7"), "title" : "Java 教程", "author" : "张三", "phone" : "10086" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e8"), "title" : "PHP 教程", "author" : "李四", "phone" : "10086" }
{ "_id" : ObjectId("5f48781a17adfc074ccae0e9"), "title" : "Python 教程", "author" : "王五", "phone" : "19999999999" }
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