Question

I am working with a legacy database tying together multiple tables (4 INNER JOINS and an OUTER LEFT JOIN); because of this and how the tables have to be joined together, it’s really hard to consolidate the data. I’ve gotten this far:

+---------------------------------------------------------------------------+
| EmployeeName | HireDate | Title | Mandatory30 | Mandatory90 | MandatoryPA |
+---------------------------------------------------------------------------+
| Stewart, P.  | 1/1/01   | CO    | 1/1/02      | NULL        | NULL        |
| Stewart, P.  | 1/1/01   | CO    | NULL        | 1/2/12      | NULL        |
| Frakes, J.   | 5/5/05   | XO    | 5/5/05      | NULL        | NULL        |
| Frakes, J.   | 5/5/05   | XO    | NULL        | 5/6/05      | NULL        |
+---------------------------------------------------------------------------+

How can I consolidate this into something closer to the following?

+---------------------------------------------------------------------------+
| EmployeeName | HireDate | Title | Mandatory30 | Mandatory90 | MandatoryPA |
+---------------------------------------------------------------------------+
| Stewart, P.  | 1/1/01   | CO    | 1/1/02      | 1/2/12      | NULL        |
| Frakes, J.   | 5/5/05   | XO    | 5/5/05      | 5/6/05      | NULL        |
+---------------------------------------------------------------------------+

There are actually 5 of these MandatoryN fields but hopefully that doesn’t make too much of a difference in the solution.

Answer 1

Try something like this:

SELECT EMPLOYEENAME, 
       HIREDATE, 
       TITLE, 
       Max(MANDATORY30) AS Mandatory30, 
       Max(MANDATORY90) AS Mandatory90, 
       Max(MANDATORYPA) AS MandatoryPA 
  FROM TABLE 
 GROUP BY EMPLOYEENAME, 
          HIREDATE, 
          TITLE 

You can add as many fields as you want/need.