在MongoDB中使用OR运算符查找值并格式化结果。
使用$or运算符获取值并格式化结果，请使用“pretty()”。让我们创建一个包含文档的集合-
> db.demo304.insertOne({"StudentName":"Chris","StudentAge":23});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4ea3ccf8647eb59e562034")
}
> db.demo304.insertOne({"StudentName":"David","StudentAge":22});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4ea3d7f8647eb59e562035")
}
> db.demo304.insertOne({"StudentName":"Mike","StudentAge":24});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4ea3e2f8647eb59e562036")
}
> db.demo304.insertOne({"StudentName":"Carol","StudentAge":22});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e4ea3eef8647eb59e562037")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo304.find();
这将产生以下输出-
{ "_id" : ObjectId("5e4ea3ccf8647eb59e562034"), "StudentName" : "Chris", "StudentAge" : 23 }
{ "_id" : ObjectId("5e4ea3d7f8647eb59e562035"), "StudentName" : "David", "StudentAge" : 22 }
{ "_id" : ObjectId("5e4ea3e2f8647eb59e562036"), "StudentName" : "Mike", "StudentAge" : 24 }
{ "_id" : ObjectId("5e4ea3eef8647eb59e562037"), "StudentName" : "Carol", "StudentAge" : 22 }以下是在MongoDB中使用OR运算符获取值的查询-
> db.demo304.find({ $or: [{ "StudentName": "David" }, { "StudentAge":22} ] } ).pretty();这将产生以下输出-
{
"_id" : ObjectId("5e4ea3d7f8647eb59e562035"),
"StudentName" : "David",
"StudentAge" : 22
}
{
"_id" : ObjectId("5e4ea3eef8647eb59e562037"),
"StudentName" : "Carol",
"StudentAge" : 22
}