[英]Grouping by just the date in Linq2DB
我正在尝试在C#中使用Linq2Db生成一个SQL查询。 我要生成的查询是这样的:
SELECT
cast([t1].[StartTime] as date) as [StartTime1],
Count(*) as [WebpageVisits],
Sum([t1].[PageCount]) as [SumOfViewsOfPages]
FROM
[myserver].[dbo].[TrackData] [t1]
GROUP BY cast([t1].[StartTime] as date)
我要使用的Linq代码是这样的:
var query = from table in dataContext.TrackData(tablePath)
group table by new { table.StartTime.Date } into grp
select new { day = grp.Key.Date, numVisitors = grp.Count(), totalPageViews = grp.Sum(table2 => table2.PageCount)};
返回的查询是
-- SqlServer.2008
SELECT
[t1].[StartTime],
Count(*) as [c1],
Sum([t1].[PageCount]) as [c2]
FROM
[myserver].[dbo].[TrackData] [t1]
GROUP BY
Convert(Date, [t1].[StartTime]),
[t1].[StartTime]
为什么多余的[t1]。[StartTime]出现在这里? 这将导致结果未根据日期分组。 如何生成我要使用Linq生成的SQL查询?
尝试分组删除匿名类型:
group table by table.StartTime.Date into grp
如果要按多个列分组,则应使用匿名类型。 我尝试在LinqPad中进行查询,但无法模拟相同的行为,但这是将来应遵循的原则
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