将 AND 和 OR 结合的 MongoDB 查询?
为了将 AND 和 OR 结合在 MongoDB 中,我们首先使用文档创建一个集合 −
>db.combinedAndOrDemo.insertOne({"StudentFirstName":"John","StudentAge":23,"StudentSkill":"MongoDB"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd306dcb64f4b851c3a13e2") } >db.combinedAndOrDemo.insertOne({"StudentFirstName":"Larry","StudentAge":21,"StudentSkill":"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd306f3b64f4b851c3a13e3") } >db.combinedAndOrDemo.insertOne({"StudentFirstName":"Sam","StudentAge":24,"StudentSkill":"SQL Server"}); { "acknowledged" : true, "insertedId" : ObjectId("5cd30701b64f4b851c3a13e4") }
以下是使用 find() 方法显示集合中所有文档的查询 −
> db.combinedAndOrDemo.find().pretty();
这将产生以下输出 −
{ "_id" : ObjectId("5cd306dcb64f4b851c3a13e2"), "StudentFirstName" : "John", "StudentAge" : 23, "StudentSkill" : "MongoDB" } { "_id" : ObjectId("5cd306f3b64f4b851c3a13e3"), "StudentFirstName" : "Larry", "StudentAge" : 21, "StudentSkill" : "MySQL" } { "_id" : ObjectId("5cd30701b64f4b851c3a13e4"), "StudentFirstName" : "Sam", "StudentAge" : 24, "StudentSkill" : "SQL Server" }
以下是 AND 和 OR 的组合查询 −
> db.combinedAndOrDemo.find( {"$or":[ {"$and": [{"StudentFirstName": "John"}, {"_id": ObjectId("5cd306dcb64f4b851c3a13e2")}] }, {"StudentSkill" : "MongoDB" } ] } );
这将产生以下输出 −
{ "_id" : ObjectId("5cd306dcb64f4b851c3a13e2"), "StudentFirstName" : "John", "StudentAge" : 23, "StudentSkill" : "MongoDB" }
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