Question

I am using dynamic where clause with Entity Framework 4.0 to filter the results.

Like

ObjectQuery<T> tmp =  _context.MyTable.where("it.CreatedAt = @p0");

@p0 is a object parameter

This works perfectly fine.

But the problem is i want to something like:

where("CAST(it.CreatedAt as Date) = @p0");

And
where(“SqlServer.CAST(it.CreatedAt as Date) = @p0”);

Both of them failed.

Any help is appreciated

UPDATE:

Error Info:

Type ‘Date’ could not be found. Make sure that the required schemas are loaded and that the namespaces are imported correctly.

And the where query is

 it.IsDeleted = true  and (  it.OrganizationName ='05 sep 2012' OR  Cast( it.CreatedAt as Date )  =@p4 OR  1=0 ) 

The Object Parameter is already supplied.

The value currently passing is ‘9/5/2012 12:00:00 AM’
and Like:

string temp = SearchedQuery.Trim();
 DateTime res;
 if (DateTime.TryParse(temp, out res))
{
 query += ((" Cast( it." + field.Name +  " as Date )  =@p" + i + ""));

 ObjectParameter pr = new ObjectParameter("p" + i, res);

 param.Add(pr);

 query += " OR ";
}

Answer 1

This worked for me. This is not perfect but worked in some case in which i want. We can clean it more also

 string temp = SearchedQuery.Trim();
 DateTime res;
 if (DateTime.TryParse(temp, out res))
 {
 query += ((" ( it." + field.Name + " >@p" + i + ""));

 query += " AND ";

 ObjectParameter pr = new ObjectParameter("p" + i, res);

 i++;

 query += ((" it." + field.Name + " <@p" + i + " ) "));

 ObjectParameter pr1 = new ObjectParameter("p" + i, res.AddDays(1));

 param.Add(pr);
 param.Add(pr1);


 query += " OR ";
}