Change "Expiration Date" font color if within 30 days or already expired?

Question

Not sure the best approach to do this, the application is older which is why I'm having so much trouble generating this. I read about doing a CASE statement but I don't have much SQL experience. Any help is appreciated and answers will be respected. Thanks. Also, there's no design to this, the people who wrote the application used placeholders and all the data comes form this huge file, which is beyond me. I don't know why because I've never seen anything like this. It's a monster.

'-
Dim TemplateColumnCDLExpiration As System.Web.UI.WebControls.TemplateColumn
TemplateColumnCDLExpiration = New System.Web.UI.WebControls.TemplateColumn
If Me.AllowSorting Then
    TemplateColumnCDLExpiration.SortExpression = "CDLExpiration"
End If
TemplateColumnCDLExpiration.ItemTemplate = 
    New JAG.WebUI.Controls.IEditGridTemplate(ListItemType.Item, 
        "CDLExpiration", 
        JAG.WebUI.Controls.tEditGridItemControlType.Label)
TemplateColumnCDLExpiration.HeaderText = "CDL Expiration"
MyBase.Columns.Add(TemplateColumnCDLExpiration)
'-

Answer 1

OK, I'll give you the answer to your CASE question, but you have to promise that you'll read the considerations below. :)

I'm using Oracle SQL; I don't know if the syntax is different for other SQL implementations. Here's an example of a dummy query to show the syntax:

SELECT 
  CASE 
    WHEN (sysdate - TO_DATE('04/09/2013', 'mm/dd/yyyy') > 30) THEN 'red'
    ELSE 'black'
  END text_color
FROM dual;

The code in the parenthesis after the WHEN is the test. It compares the current date to April 9th and asks, "Is April 9th more than 30 days ago?" If so, it returns 'red' as the value of text_color. If that condition is false, it returns 'black'. Here's a more generalized form:

SELECT 
  CASE 
    WHEN (sysdate - :date_to_check > :expiration_days) THEN 'red'
    ELSE 'black'
  END text_color
FROM :my_table;

---

Considerations

You don't need this nasty piece of logic in SQL. The check for X number of days passing since the given date is not database logic. Fetching a date is database logic, deciding how many days have elapsed from that date until today could be argued as either DB logic or business logic, but deciding the text color is definitely display logic, meaning you should be modifying your .NET code, not your SQL. What happens if you need to change the display colors? The date check remains the same, but you have to modify...your SQL? SQL modifications should only need to happen if the data that is being retrieved or stored is modified. The bottom line is that this is not a clean separation of concerns.