如何使用deleteMany()删除MongoDB中的多个文档？
首先让我们创建一个包含文档的集合-
> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Larry"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce00b07bf3115999ed51214")
}
> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce00b0bbf3115999ed51215")
}
> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce00b0fbf3115999ed51216")
}
> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce00b12bf3115999ed51217")
}
> db.deleteMultipleDocumentsDemo.insertOne({"StudentFirstName":"Carol"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ce00b18bf3115999ed51218")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.deleteMultipleDocumentsDemo.find();
这将产生以下输出-
{ "_id" : ObjectId("5ce00b07bf3115999ed51214"), "StudentFirstName" : "Larry" }
{ "_id" : ObjectId("5ce00b0bbf3115999ed51215"), "StudentFirstName" : "Chris" }
{ "_id" : ObjectId("5ce00b0fbf3115999ed51216"), "StudentFirstName" : "David" }
{ "_id" : ObjectId("5ce00b12bf3115999ed51217"), "StudentFirstName" : "Bob" }
{ "_id" : ObjectId("5ce00b18bf3115999ed51218"), "StudentFirstName" : "Carol" }以下是在MongoDB中删除多个文档的查询-
> db.deleteMultipleDocumentsDemo.deleteMany({StudentFirstName: {$in: ["Larry", "David", "Carol"]}});
{ "acknowledged" : true, "deletedCount" : 3 }让我们再次显示文档-
> db.deleteMultipleDocumentsDemo.find();
这将产生以下输出-
{ "_id" : ObjectId("5ce00b0bbf3115999ed51215"), "StudentFirstName" : "Chris" }
{ "_id" : ObjectId("5ce00b12bf3115999ed51217"), "StudentFirstName" : "Bob" }