MongoDB如何在同一个键上实现多个OR条件的查询
为此，只需使用$or一次。让我们创建一个包含文档的集合-
> db.demo551.insertOne({"Name":"John"});{
"acknowledged" : true, "insertedId" : ObjectId("5e8e36d39e5f92834d7f05e5")
}
> db.demo551.insertOne({"Name":"Chris Brown"});{
"acknowledged" : true, "insertedId" : ObjectId("5e8e36d89e5f92834d7f05e6")
}
> db.demo551.insertOne({"Name":"John Doe"});{
"acknowledged" : true, "insertedId" : ObjectId("5e8e36de9e5f92834d7f05e7")
}
> db.demo551.insertOne({"Name":"John Smith"});{
"acknowledged" : true, "insertedId" : ObjectId("5e8e36e59e5f92834d7f05e8")
}
> db.demo551.insertOne({"Name":"Carol"});{
"acknowledged" : true, "insertedId" : ObjectId("5e8e36ec9e5f92834d7f05e9")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo551.find();
这将产生以下输出-
{ "_id" : ObjectId("5e8e36d39e5f92834d7f05e5"), "Name" : "John" }
{ "_id" : ObjectId("5e8e36d89e5f92834d7f05e6"), "Name" : "Chris Brown" }
{ "_id" : ObjectId("5e8e36de9e5f92834d7f05e7"), "Name" : "John Doe" }
{ "_id" : ObjectId("5e8e36e59e5f92834d7f05e8"), "Name" : "John Smith" }
{ "_id" : ObjectId("5e8e36ec9e5f92834d7f05e9"), "Name" : "Carol" }以下是要在同一个键上实现OR条件的查询-
> db.demo551.find({$or:[
... {"Name" : {$eq : "Carol"}},
... {Name: {$eq:"John"}}
... ]
... });这将产生以下输出-
{ "_id" : ObjectId("5e8e36d39e5f92834d7f05e5"), "Name" : "John" }
{ "_id" : ObjectId("5e8e36ec9e5f92834d7f05e9"), "Name" : "Carol" }