Finding specific duplicates when one field is different <p>I have a SQL DB table that has some data duplication. I need to find records based on the fact that none of the "duplicate" records has a value of Null value in one of the fields. i.e.</p> <pre><code>ID Name StartDate 1 Fred 1/1/1945 2 Jack 2/2/1985 3 Mary 3/3/1999 4 Fred null 5 Jack 5/5/1977 6 Jack 4/4/1985 7 Fred 10/10/2001 </code></pre> <p>In the example above I need to find Jack and Mary but not Fred. I assume some sort of Self Join or Union but have run into a mental block on what exactly would give me my desired results. </p>