The specified type member 'Date' is not supported in LINQ to Entities Exception

Question

I got a exception while implementing the following statements.

 DateTime result;
 if (!DateTime.TryParse(rule.data, out result))
     return jobdescriptions;
 if (result < new DateTime(1754, 1, 1)) // sql can't handle dates before 1-1-1753
     return jobdescriptions;
 return jobdescriptions.Where(j => j.JobDeadline.Date == Convert.ToDateTime(rule.data).Date );

Exception

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

I know what the exception means but i don't know how to get rid of it. Any help?

Answer 1

LINQ to Entities cannot translate most .NET Date methods (including the casting you used) into SQL since there is no equivalent SQL.

The solution is to use the Date methods outside the LINQ statement and then pass in a value. It looks as if Convert.ToDateTime(rule.data).Date is causing the error.

Calling Date on a DateTime property also cannot be translated to SQL, so a workaround is to compare the .Year .Month and .Day properties which can be translated to LINQ since they are only integers.

var ruleDate = Convert.ToDateTime(rule.data).Date;
return jobdescriptions.Where(j => j.Deadline.Year == ruleDate.Year 
                       && j.Deadline.Month == ruleDate.Month 
                       && j.Deadline.Day == ruleDate.Day);