Re: Embedded SQL examples (Chris Chambers (M&M Software))

    cobol400-l-request@xxxxxxxxxxxx                                           
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    01/09/2004 01:00 PM                      Subject:        COBOL400-L       
    Please respond to cobol400-l     Digest, Vol 2, Issue 8                   

   What you're trying to do would require *dynamic* SQL rather than *static*.
    If you do your CRTSQL... command, you'll notice the parameter
   TOSRCFILE(QTEMP/QSQLTEMP).  Change this to another file (not the one where
   your original source is kept).  When you submit your CRTSQL... command,
   your actually submitting an 'precompiler' which translates your embedded
   SQL into calls to the database routines with files, fields, (aka tables,
   columns), and variables loaded into parameters that the database routines
   can use.  The precompiler then submits a CRTCBL... command for the source
   it generates.  This works fine for *static* SQL, but if you want to
   dynamically change the files (aka tables) and fields (aka columns), you
   need to use *dynamic* SQL.  
   Check out the iSeries Information Center under "Database: Manuals: 'SQL
   Programming with Host Languages'".  Unfortunately, it includes dynamic SQL
   examples only for ILE RPG and not for COBOL.  However, the concept is
   pretty straight forward.  You load a host variable with your statement,
   prepare it, and so forth.

   HTH
   Original message:
   ----------------------------------------------------------------------

   date: Thu, 8 Jan 2004 21:07:32 -0000
   from: "Chris Chambers \(M&M Software\)"
                   <cchambers@xxxxxxxxxxxxxxxxxxxxxx>
   subject: [COBOL400-L] Embedded SQL examples

   Hi there,

   I'm trying to write an UPDATE statement within a COBOL program where the
   Filename as well as the values to update are all parameterised.

   I can get the FILENAME to work if I use the PREPARE statement but not the
   values - and I can get the values to work in a straightforward UPDATE but
   the FILENAME is then not allowed as a parameter.

   I had imagined I may be able to construct something like this:

   EXEC-SQL
      UPDATE    :FILENAME
          SET     :FIELDNAME1    TO    :VALUE1
              WHERE     :FIELDNAME2    =    :VALUE2
   END-EXEC  

   If I string it altogether as a prepared statement the resulting command
   does not execute from within the program as it assumes the values to be a
   fieldname but if I copy and paste the same command into STRSQL it works
   fine - so what am I doing wrong?

   Anyone got some examples that work??

   Many Thanks,

   Chris