title: How to design SQL tables to allow for multiple parent table options?
body: <p>Looking into creating a series of tables in a reporting hierarchy and am more or less drawing a blank.</p>
  
  <p>While tables in this structure can only have one parent, how do I structure the fields so that they point to the right parent table?  As you'll see in my example below, a row's parent table can differ. </p>
  
  <pre><code>                  ARRANGEMENT
                    /           \
             MATTERS            ISSUES 
                |                     |
              PHASES                MATTERS
            /       \                 |
       ISSUES      TASKS            PHASES
       /    \        |             /      \
   TITLES  TASKS   ISSUES       TASKS    TITLE  
             |        |           |
          TITLES   TITLES       TITLE 
  </code></pre>
  
  <p>Essentially, is it best to have each "branch" have a unique table (even though Tasks in branch 1 has the same data structure as branch 2 or 3), or is it best to have the records identify which table is their parent?</p>
  
  <pre><code>Arrangement(ID)
  Matters(ParentTable, ParentID, ID)
  Phases(ParentTable, ParentID, ID)
  Issues(ParentTable,ParentID, ID)
  Titles(ParentTable,ParentID, ID)
  Tasks(ParentTable,ParentID, ID)
  </code></pre>
  
  <p>The above doesn't seem right to me at all.  Help?</p>