如何使用MongoDB计算以小时为单位的时间戳差异？
要计算时间戳差异，请使用聚合框架。首先让我们创建一个包含文档的集合-
> db.timestampDifferenceDemo.insertOne({
"MovieBeginningTime": new ISODate("2019-05-12 10:20:30"),
"MovieEndingTime":new ISODate("2019-05-12 12:30:20")
});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd7ba1f6d78f205348bc644")
}
> db.timestampDifferenceDemo.insertOne({
"MovieBeginningTime": new ISODate("2019-05-12 04:00:00"),
"MovieEndingTime":new ISODate("2019-05-12 07:10:00")
});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd7ba3b6d78f205348bc645")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.timestampDifferenceDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd7ba1f6d78f205348bc644"),
"MovieBeginningTime" : ISODate("2019-05-12T10:20:30Z"),
"MovieEndingTime" : ISODate("2019-05-12T12:30:20Z")
}
{
"_id" : ObjectId("5cd7ba3b6d78f205348bc645"),
"MovieBeginningTime" : ISODate("2019-05-12T04:00:00Z"),
"MovieEndingTime" : ISODate("2019-05-12T07:10:00Z")
}以下是计算MongoDB中时间戳差异的查询（以小时为单位）-
> db.timestampDifferenceDemo.aggregate([
{$project: {
DifferenceInHours: {$divide: [{$subtract: ["$MovieEndingTime", "$MovieBeginningTime"]}, 3600000]}
}}
]);这将产生以下输出-
{ "_id" : ObjectId("5cd7ba1f6d78f205348bc644"), "DifferenceInHours" : 2.1638888888888888 }
{ "_id" : ObjectId("5cd7ba3b6d78f205348bc645"), "DifferenceInHours" : 3.1666666666666665 }