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IT18381: DB2 MAY RETURN INCORRECT RESULTS IF USING A CASE STATEMENT TO COMPARE FIXED CHAR/GRAPHIC STRINGS IN VARCHAR2 COMPATIBILITY MODE

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APAR status

  • Closed as program error.

Error description

  • When comparing fixed character or graphic strings where either
    side uses a CASE statement, DB2 may return incorrect results in
    VARCHAR2 compatibility mode.
    
    Example:
    
    CREATE TABLE T(C1 CHAR(4))
    INSERT INTO T VALUES ('M')
    SELECT * FROM T WHERE C1 = CASE WHEN 1=1 THEN 'M' END
    
    Incorrect Result:
    
    C1
    ----
    
      0 record(s) selected.
    

Local fix

  • From the example above, cast the CASE statement to a fixed
    character string of the desired length:
    
    SELECT * FROM T WHERE C1 = CAST((CASE WHEN 1=1 THEN 'M' END) AS
    CHAR(1))
    
    C1
    --------
    M
    
      1 record(s) selected.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * ALL                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 11.1 Mod 2 Fix Pack 2 or higher               *
    ****************************************************************
    

Problem conclusion

  • First fixed in DB2 11.1 Mod 2 Fix Pack 2
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT18381

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-12-13

  • Closed date

    2017-06-23

  • Last modified date

    2017-06-23

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

    IT18343

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

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
29 June 2020