Re: Embedded SQL -- RPG400-L


1)  Declare multiple cursors like C1cursor, C2cursor, etc.

2)  Evaluate using PREPARE and EXECUTE to build an 'on-the-fly' SQL
statement

3)  Structure your SQL statement for maximum flexibility.  In your example
let's pretend you had the following:
C    SELECT
C    WHEN CHOICE = 'A'
C/EXEC SQL
C+ Select COL1, COL2, COL3
C+ from TABLEA
C+ where COL4=:X
C/END-EXEC
C    WHEN CHOICE='B'
C/EXEC SQL
C+ Select COL1, COL2, COL3
C+ from TABLEA
C+ where COL4 between :Y and :Z
C/END-EXEC
C    WHEN CHOICE='C'
C/EXEC SQL
C+ Select COL1, COL2, COL3
C+ from TABLEA
C/END-EXEC
C    ENDSL

Restructure this into:
C    SELECT
C    WHEN CHOICE = 'A'
C     Eval  Y=X
C     Eval  Z=X
C    WHEN CHOICE='B'
C     WHEN  CHOICE='C'
C     Eval  Y=*loval
C     Eval  Z=*hival
C    ENDSL
C/EXEC SQL
C+ Select COL1, COL2, COL3
C+ from TABLEA
C+ where COL4 between :Y and :Z
C/END-EXEC

In this case you would always use the BETWEEN instead of choosing.  This
same technique has been used by SQL and OPNQRYF.
Rob Berendt

==================
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                    "Mike Naughton"                                             
                                       
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                    12/11/00 12:52 PM                                           
                                       
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I have been experimenting with embedded SQL, using Barbara's example
program as a guide (thanks, Barbara!). In general, it works great, but I'm
running into one problem that I can't seem to get around. If I only have
one "declare cursor" statement, I'm fine, but it I try to have more than
one
e.g.
C    SELECT
C    WHEN CHOICE = 'A'
C/EXEC SQL
C+ declare C1cursor for
C+ <some stuff here>
C/END-EXEC
C    WHEN CHOICE='B'
C/EXEC SQL
C+ declare C1cursor for
C+ <other stuff here>
C/END-EXEC
C    ENDSL

I get a compile error "cursor C1 already defined" for the second statement
(and all subsequent ones). I've tried IFs and SELECTs; I've tried putting
it in the main flow or off in a subroutine -- nothing seems to work!

Am I missing something?

Thanks!

Mike Naughton
Senior Programmer/Analyst
Judd Wire, Inc.
124 Turnpike Road
Turners Falls, MA  01376
413-863-4357 x444
mnaughton@juddwire.com


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