MongoDB查询仅在特定时间搜索记录？
为此，请使用$hour运算符。让我们首先创建一个文档集合，其中一个字段作为日期-
> db.mongoDbSearchForHoursDemo.insertOne({"CustomerName":"Larry","OrderDatetime":new ISODate("2019-01-31 09:45:50")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd6e8a86d78f205348bc62a")
}
> db.mongoDbSearchForHoursDemo.insertOne({"CustomerName":"Larry","OrderDatetime":new ISODate("2019-02-21 01:10:01")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd6e8b86d78f205348bc62b")
}
> db.mongoDbSearchForHoursDemo.insertOne({"CustomerName":"Larry","OrderDatetime":new ISODate("2019-04-01 04:10:11")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd6e8e26d78f205348bc62c")
}
> db.mongoDbSearchForHoursDemo.insertOne({"CustomerName":"Larry","OrderDatetime":new ISODate("2019-05-11 08:53:01")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd6e8f26d78f205348bc62d")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.mongoDbSearchForHoursDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd6e8a86d78f205348bc62a"),
"CustomerName" : "Larry",
"OrderDatetime" : ISODate("2019-01-31T09:45:50Z")
}
{
"_id" : ObjectId("5cd6e8b86d78f205348bc62b"),
"CustomerName" : "Larry",
"OrderDatetime" : ISODate("2019-02-21T01:10:01Z")
}
{
"_id" : ObjectId("5cd6e8e26d78f205348bc62c"),
"CustomerName" : "Larry",
"OrderDatetime" : ISODate("2019-04-01T04:10:11Z")
}
{
"_id" : ObjectId("5cd6e8f26d78f205348bc62d"),
"CustomerName" : "Larry",
"OrderDatetime" : ISODate("2019-05-11T08:53:01Z")
}以下是查询特定时间的查询。在这里，我们将获得特定时间8和1的记录。输出将显示两个时间（小时）的ID-
>db.mongoDbSearchForHoursDemo.aggregate([{$project:{SpecificHours:{$hour:"$OrderDatetime"}}},
{$match:{SpecificHours:{"$in":[08,01]}}}]);这将产生以下输出-
{ "_id" : ObjectId("5cd6e8b86d78f205348bc62b"), "SpecificHours" : 1 }
{ "_id" : ObjectId("5cd6e8f26d78f205348bc62d"), "SpecificHours" : 8 }