EF comparing strings representing SAP dates in a linq query?

Question

In my table there is a varchar field which contains dates. (That's how SAP stores dates) Anyway to run a query against this field similar to:

from c in db.Set<MyTable>()
   where c.Date >= "20120921" && c.Date <= "20121021"
   select c

I tried to do a String.Compare, but EF can't translate that to sql.

where Stirng.Compare(c.Date, "20120921") >= 0

I also tried to convert both strings to int and do the comparison, and again EF doesn't support that.

Answer 1

You can try using SqlFunctions.DateDiff method overload that takes three strings, like this:

var res = from c in db.Set<MyTable>()
   where SqlFunctions.DateDiff("dd", c.Date, "20120921") >= 0
      && SqlFunctions.DateDiff("dd", c.Date, "20121021") < 0
   select c