在单个MongoDB查询中更新多行？

使用的概念initializeUnorderedBulkOp()。首先让我们创建一个包含文档的集合-

>db.upDateMultipleRowsDemo.insertOne({"CustomerName":"John","CustomerPurchaseAmount":500});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd6ceb06d78f205348bc626")
}
>db.upDateMultipleRowsDemo.insertOne({"CustomerName":"Chris","CustomerPurchaseAmount":700});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd6ceb26d78f205348bc627")
}
>db.upDateMultipleRowsDemo.insertOne({"CustomerName":"David","CustomerPurchaseAmount":50});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd6ceb36d78f205348bc628")
}
>db.upDateMultipleRowsDemo.insertOne({"CustomerName":"Larry","CustomerPurchaseAmount":1900});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cd6ceb46d78f205348bc629")
}

以下是在find()方法的帮助下显示集合中所有文档的查询-

> db.upDateMultipleRowsDemo.find().pretty();

这将产生以下输出-

{
   "_id" : ObjectId("5cd6ceb06d78f205348bc626"),
   "CustomerName" : "John",
   "CustomerPurchaseAmount" : 500
}
{
   "_id" : ObjectId("5cd6ceb26d78f205348bc627"),
   "CustomerName" : "Chris",
   "CustomerPurchaseAmount" : 700
}
{
   "_id" : ObjectId("5cd6ceb36d78f205348bc628"),
   "CustomerName" : "David",
   "CustomerPurchaseAmount" : 50
}
{
   "_id" : ObjectId("5cd6ceb46d78f205348bc629"),
   "CustomerName" : "Larry",
   "CustomerPurchaseAmount" : 1900
}

以下是在单个查询中更新多行的查询-

> var manyUpdateValue = db.upDateMultipleRowsDemo.initializeUnorderedBulkOp();

> manyUpdateValue.find({ _id: ObjectId("5cd6ceb06d78f205348bc626")}).updateOne({$set:{"CustomerName":"Bob" }});

> manyUpdateValue.find({ _id: ObjectId("5cd6ceb36d78f205348bc628")}).updateOne({$set:{"CustomerPurchaseAmount":56544444}});

> manyUpdateValue.execute();
BulkWriteResult({
   "writeErrors" : [ ],
   "writeConcernErrors" : [ ],
   "nInserted" : 0,
   "nUpserted" : 0,
   "nMatched" : 2,
   "nModified" : 2,
   "nRemoved" : 0,
   "upserted" : [ ]
})

让我们再次检查所有文件-

> db.upDateMultipleRowsDemo.find().pretty();

这将产生以下输出-

{
   "_id" : ObjectId("5cd6ceb06d78f205348bc626"),
   "CustomerName" : "Bob",
   "CustomerPurchaseAmount" : 500
}
{
   "_id" : ObjectId("5cd6ceb26d78f205348bc627"),
   "CustomerName" : "Chris",
   "CustomerPurchaseAmount" : 700
}
{
   "_id" : ObjectId("5cd6ceb36d78f205348bc628"),
   "CustomerName" : "David",
   "CustomerPurchaseAmount" : 56544444
}
{
   "_id" : ObjectId("5cd6ceb46d78f205348bc629"),
   "CustomerName" : "Larry",
   "CustomerPurchaseAmount" : 1900
}