Canonical Function “EntityFunctions.TruncateTime” does not exist in MYSQL

Question

I\'m trying to run this query:

DateTime DDate=DateTime.Today; //Today\'s date without Time
var v= db.measurements.Where(m => EntityFunctions.TruncateTime(         


        

Answer 1

I couldn't resolve it, so I just created a Function named "TruncateTime" in the database.

Create FUNCTION TruncateTime(dateValue DateTime) RETURNS date
return Date(dateValue);

And it works, but I don't like it.

These people did similar things:

Alternative to EntityFunctions.AddSeconds for MySQL

CurrentUtcDateTime does not exist - Entity Framework and MySql

So now I think that might be unnecessary and I can just call it directly from the database and still get entities, something like this:

var x = db.ExecuteStoreQuery<Measurement>(@"SELECT field1,field2
FROM   Measurements
WHERE  Date(InDate) = {0}", DDate);

And that's all.

Answer 2

The approach in A Torres' response works, but it felt a bit hacky for me, so I have found another approach (This works for EF6, for EF5 a similar approach exists, but I can't test it):

1. Create class DatabaseFunctions and add the following code to it:

   [Function(FunctionType.BuiltInFunction, "Date")]
   public static DateTime? Date(DateTime? dateValue) 
       => Function.CallNotSupported<DateTime>();
   

2. Add the following line to OnModelCreating in your DbContext

   protected override void OnModelCreating(DbModelBuilder modelBuilder){
       modelBuilder.Conventions.Add(new FunctionConvention<DatabaseFunctions>())
       // ...
   }
   

3. Use DatabaseFunctions.Date instead of EntityFunctions.TruncateTime.