SQL Server: Add translation for TODATETIMEOFFSET()

[EmperorArthur]

Issue

I am working with a SQL database that stores timestamps using "datetime", but want to convert them to a "datetimeoffset" in SQL without having to write my own function mapping.

Recommended priority.

Low.

This fills a missing niche in the list of built in function mappings.

• Custom function mapping is already supported.
• Though a kludge, EF.Functions.DateTimeOffsetFromParts(dateTime.Year, ...) could be used.

Proposed Solution

Map the TODATETIMEOFFSET function to "EF.Functions.DateTimeOffsetFromDateTime". Handling the TimeSpan.TotalMinutes conversion.

[roji]

Instead of introducing EF.Functions.DateTimeOffsetFromParts, we could simply translate the DateTimeOffset constructo which accepts a DateTime (https://learn.microsoft.com/en-us/dotnet/api/system.datetimeoffset.-ctor?view=net-9.0#system-datetimeoffset-ctor(system-datetime-system-timespan)).

Am noting that we will be ignoring the DateTime.Kind of the DateTime argument, as we already ignore it elsewhere (e.g. when persisting the DateTime to the database, which cannot preserve it).