C# – How to perform Date Comparison in EF query

cdatetimedatetime-comparisonlinqlinq-to-entities

Please help.
I am trying to figure out how to use DATE or DATETIME for comparison in a linq query.

Example:
If I wanted all Employee names for those who started before today, I would do something like this in SQL:

SELECT EmployeeNameColumn
FROM EmployeeTable
WHERE StartDateColumn.Date <= GETDATE() //Today

But what about linq?

DateTime startDT = //Today

var EmployeeName =  
from e in db.employee
where e.StartDateColumn <= startDT

The above WHERE doesn't work:

Exception Details: System.NotSupportedException: The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

Best Answer

Use the class DbFunctions for trimming the time portion.

using System.Data.Entity;

var bla = (from log in context.Contacts
           where DbFunctions.TruncateTime(log.ModifiedDate) 
                              ==  DbFunctions.TruncateTime(today.Date)
           select log).FirstOrDefault();

Source: http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/84d4e18b-7545-419b-9826-53ff1a0e2a62/

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