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
}