实体框架。 SQL分组依据到EF分组依据

Question

I am trying to define a standard way to group by year, by month, by day, by hour, etc ...

By reading some SQL documentation it seems the most efficient way would be to use:

GROUP BY dateadd(month, datediff(month, 0, CreatedDate), 0)

Note the "month", "year", ...

I then tried to replicate this using:

.GroupBy(x => SqlFunctions.DateAdd("month", SqlFunctions.DateDiff("month", 0, x.Created), 0))

.GroupBy(x => EntityFunctions.AddMonths(EntityFunctions.DiffMonths(0, x.Created)))

However, both expression failed to compile ...

And I am not sure if this is the way to do it?

How can I correctly replicate that SQL code line in EF?

Answer 1

I don't understand Why would you want to use the standard sql to do that any way, however this can be done easily using LINQ and it would be more standard , grouping by an anonymous type for example like this:

.GroupBy( x => new 
               {
                  month = x.CreatedDate.Month,
                  year = x.CreatedDate.Year,
                  ...
               });