MongoDB查询仅搜索月和日？
要仅搜索月和日，请使用聚合框架。
首先让我们创建一个包含文档的集合-
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2019-04-27")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefbcaeef71edecf6a1f6b2")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2018-04-30")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefbcb7ef71edecf6a1f6b3")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2018-04-27")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefbcbcef71edecf6a1f6b4")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2016-04-27")});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefbdaaef71edecf6a1f6b5")
}在find()方法的帮助下显示集合中的所有文档-
> db.monthAndDayDemo.find();
输出结果
{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "LoginDate" : ISODate("2019-04-27T00:00:00Z") }
{ "_id" : ObjectId("5cefbcb7ef71edecf6a1f6b3"), "LoginDate" : ISODate("2018-04-30T00:00:00Z") }
{ "_id" : ObjectId("5cefbcbcef71edecf6a1f6b4"), "LoginDate" : ISODate("2018-04-27T00:00:00Z") }
{ "_id" : ObjectId("5cefbdaaef71edecf6a1f6b5"), "LoginDate" : ISODate("2016-04-27T00:00:00Z") }以下是仅搜索月份和日期的查询-
{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "LoginDate" : ISODate("2019-04-27T00:00:00Z") }
> db.monthAndDayDemo.aggregate( { "$project": { "m":{"$month":"$LoginDate"},
"d": { "$dayOfMonth":"$LoginDate" } }}, { "$match":{ "m": 4, "d": 27 } } );输出结果
{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "m" : 4, "d" : 27 }
{ "_id" : ObjectId("5cefbcbcef71edecf6a1f6b4"), "m" : 4, "d" : 27 }
{ "_id" : ObjectId("5cefbdaaef71edecf6a1f6b5"), "m" : 4, "d" : 27 }