PH55098: IBM DEVELOPER FOR Z/OS V16.1 - SQL QUERY PRODUCES INCORRECT RESULTS WHEN JOINING TABLES CONTAINING THE SAME COLUMN NAME

APAR status

• Closed as program error.

Error description

• Joining DB2 tables that contain the same column names produces
  incorrect SQL query results.  Instead of displaying the contents
  from each of the columns with the same name, the results only
  show the data from the last table joined.
  
  Running the following sample query will display B.DESC in both
  the A.DESC column as well as the B.DESC column.
  
  SELECT A.ID, A.DESC,
         B.ID, B.DESC
  FROM TEST.TABLE1 AS A
  LEFT JOIN TEST.TABLE2 B ON A.ID = B.ID
  

Local fix

• If you qualify the column names the issues does not occur.
  Rewrite the query above and qualify the column names.
  
  SELECT A.ID AS TABLE1_ID, A.DESC AS TABLE1_DESC,
         B.ID AS TABLE2_ID, B.DESC AS TABLE2_DESC
  FROM TEST.TABLE1 AS A
  LEFT JOIN TEST.TABLE2 B ON A.ID = B.ID
  

Problem summary

• SQL queries containing two or more columns with identical names
  would cause each of those columns to display the same values for
   a row.
  

Problem conclusion

• Result set columns with identical names will now display their
  individual values correctly.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  DEV FOR Z/OS

• Fixed component ID

  5724T0700

Applicable component levels