Get time only of datetime

Question

I have datetime variable officeStartTime which hold datetime value as

officeStartTime = {9/24/2013 10:00:00 AM}

and I have module CHECKINOUT which contain userid, checktime and other properties.

Now what I want is to get list of CHECKINOUT entries whose time part of checktime is greater than time part of officeStartTime.

I try:

var checklist= con.CHECKINOUTs.Where(x => x.CHECKTIME.TimeOfDay > officeStartTime.TimeOfDay);

checklist contains the following error is shown:

{"The specified type member 'TimeOfDay' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported."} .

It says TimeOfDay is not supported in LINQ to Entities, if so how can I check for time part of datetime in LINQ. Is there any other way to do this? Please suggest me what to do.

Thank you.

Answer 1

Use

CreateTime(hour, minute, second)

from Date and Time Canonical Functions

Answer 2

Use EntityFunctions.CreateTime method:

var checklist= from c in con.CHECKINOUTs
               let time = EntityFunctions.CreateTime(c.CHECKTIME.Hour,
                                                     c.CHECKTIME.Minute,
                                                     c.CHECKTIME.Second)
               where time > officeStartTime.TimeOfDay
               select c;

Fluent syntax:

con.CHECKINOUTs.Where(c => EntityFunctions.CreateTime(c.CHECKTIME.Hour, c.CHECKTIME.Minute, c.CHECKTIME.Second) > officeStartTime.TimeOfDay)

Answer 3

Just as a heads up, if you are using Entity Framework Version 6.0.0.0, EntityFunctions is OUTDATED.

The same functionality can be found under DbFunctions.

So for your answer, using EF6, it would look like this:

con.CHECKINOUTs.Where(c => DbFunctions.CreateTime(c.CHECKTIME.Hour, c.CHECKTIME.Minute, c.CHECKTIME.Second) > officeStartTime.TimeOfDay)

Hope this helps!