c# Column datatype Date type (NOT DateTime)

Question

Hi All:

I want know is there good way to detect Column DataType for Date field (NOT DateTime)?

This what currently I do:

switch (dt.Columns[col].DataType.FullName)
{  
    case "System.DateTime":  
        formatedVal = Formatter.GetDateTime(val);  
        break;

    // which is NOT possible, but something equivalent am looking for
    case "System.Date":  
        formatedVal = Formatter.GetDate(val);  
        break;

    default:
        formatedVal = val.ToString();
        break;
}

Thanks a bunch. :-)

Answer 1

Nope. There is no Date type, there is only DateTime. If this is coming from a SQL Server 2008 table that uses a date column, it will be mapped to DateTime in .NET.

If you need to get at this information then you'll have to do it at the SQL level; by the time it's loaded into a DataTable, it's too late.

I'm not positive about your requirements, but it looks like you might be able to get away with just checking for midnight and using a different format for that:

DateTime dt = (DateTime)val;
return (dt == dt.Date) ? Formatter.GetDate(dt) : Formatter.GetDateTime(dt);

Answer 2

DateTime.ToString is flexible http://msdn.microsoft.com/library/zdtaw1bw.aspx

Answer 3

If you use an SqlDataReader, you can call GetSchemaTable which will give you access to the underlying SQL Server datatypes for each column - there's a full list of the schema info it returns in that linked MSDN reference. So that's one approach if you really need to get the underlying SQL Server schema.

SqlDataAdapter does have a FillSchema method, but I don't think that actually gives you the underlying db types.

Answer 4

Actually, "Date" is a built in data type in CLR, although it is now marked as "obsolete". IDEs do not even show it...

Anyway, as in any case when you want to kwnow the type of an object, I think obj.GetType().Name is not the best way to go, because you end up comparing strings when you actually wanna know if an obj is of ceratin type.

I'd go with

if (dt.Columns[col] is DateTime)
.....
else
  if (dt.Columns[col] is Date) 
   ... 

I am just showing another way of performing datatype checks. You said yourself, it os not possible to compare to "Date".