RE: Embedded SQL exists?

["Whiteman, Greg" <Greg.Whiteman@xxxxxxxxxxxxxxxx>]

You could incorporate all into one sql. For example:

     C
     C/EXEC SQL
     C+  INSERT INTO EMAILFDST
     C+    VALUES(:EMAILFDST)
     C+ WHERE NOT EXISTS
     C+    (SELECT 1 FROM EMAILFDST
     C+    WHERE EMDFIL=:EMDFIL AND
     C+    EMDCMP=:EMDCMP AND
     C+    EMDFAC=:EMDFAC AND
     C+    EMDUSR=:EMDUSR)


The insert will occur only if no row exists in file EMAILFDST for the
criteria specified in the WHERE clause



-----Original Message-----
From: darren@dekko.com [ mailto:darren@dekko.com <mailto:darren@dekko.com> ]
Sent: Wednesday, November 28, 2001 12:23 PM
To: rpg400-l@midrange.com
Subject: Embedded SQL exists?


I am running a subfile maintenance program using RPGLE and embedded SQL.
When the user specifies they want to insert a record I'm using a: (don't
read the code too closely, basically its just a SELECT with a WHERE)
     C/EXEC SQL
     C+  SELECT DISTINCT EMDFIL INTO :EMDFIL
     C+    FROM EMAILFDST
     C+    WHERE EMDFIL=:EMDFIL AND
     C+    EMDCMP=:EMDCMP AND
     C+    EMDFAC=:EMDFAC AND
     C+    EMDUSR=:EMDUSR
     C/END-EXEC

and then checking the SQL code:
     C                   If        SQLCOD<>0


to make sure the part doesn't already exist before doing the insert:
     C
     C/EXEC SQL
     C+  INSERT INTO EMAILFDST
     C+    VALUES(:EMAILFDST)
     C/END-EXEC

Is there a cleaner way of doing this?  I don't really care what the value
of EMDFIL is, its the "WHERE" that I'm really interested in verifying.
I've read the reference and programming manual from IBM and it doesn't seem
like you can incorporate this checking into the INSERT command, unless I
misunderstood.


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