Commenting sql

[rob@xxxxxxxxx]

Just wanted to pass on kudo's to a coworker who writes some outstanding 
SQL.  He had this multipage sql statement that does a full BOM explosion 
in BPCS.  He had to modify it to handle a special exception when someone 
manually changes part numbers out of the system and does something like 
have the parent included as one of the children also.
Not only  am I impressed with his grasp of SQL (all learned solely from 
the IBM reference manuals) but also by his comments.

> From the coworker (looks so much prettier in WDSC with the colors and 
all):

Here is the code for my BOM explosion using SQL.  The 'cycle' command 
prevents circular infinite loops.  NOTE: This is not a full query.

...
           , Exploded(Parent, Child, Qty
                         ,LVL, TopParent) as
            (select BPROD, BCHLD, BQREQ, 1, BPROD
               from MBMClean
             union all
             select BPROD, BCHLD, BQREQ, LVL+1
                    , TopParent
               from MBMClean
               join Exploded
                 on BPROD=Child
              // Configure BOM explosion to follow each path to its end.
              //  OrdCol controls this in a later "ORDER BY"
            ) search depth first by Child set OrdCol
              // Prevent endless loops due to circular reference
              cycle Child set cyclic_data to '1' default '0'

Rob Berendt