UPDATE Statement executing for whole table even when WHERE Clause is presen

Question

Hi Friends,
I have a problem in a stored procedure where i have written an update statement with a where clause. At a time only one row should get updated depending upon unique identifier in where clause.
But whats happening is that Update statement is getting executed for all the rows in the table neglecting the WHERE clause. I am not getting the clue as to why this is happening. Here is the stored Procedure And the update statement is in BOLD :-
CREATE OR REPLACE PROCEDURE MDMADM.proc_MDM_InsertCntryDetails
CntryMasterCode IN VARCHAR2,
CntryName IN VARCHAR2,
MDMUser IN VARCHAR2,
Exist IN INTEGER,
status IN VARCHAR2,
Inserted_By IN VARCHAR2 DEFAULT NULL,
Modified_By IN VARCHAR2 DEFAULT NULL,
Mdm_Code IN NUMBER DEFAULT 0,
Action IN VARCHAR2 DEFAULT 'add',
XGenAttNames IN VARCHAR2 DEFAULT NULL,
XGenAttValues IN VARCHAR2 DEFAULT NULL,
MirusAttNames IN VARCHAR2 DEFAULT NULL,
MirusAttValues IN VARCHAR2 DEFAULT NULL,
GenisysAttNames IN VARCHAR2 DEFAULT NULL,
GenisysAttValues IN VARCHAR2 DEFAULT NULL,
XGenModify IN VARCHAR2 DEFAULT NULL,
MirusModify IN VARCHAR2 DEFAULT NULL,
GenisysModify IN VARCHAR2 DEFAULT NULL
IS
strSQLXGen VARCHAR(1000);
strSQLMirus VARCHAR(1000);
strSQLGenisys VARCHAR(1000);
nMaxMDMCode INTEGER;
ifExist INTEGER;
NAME: proc_MDM_InsertCntryDetails
PURPOSE:
REVISIONS:
Ver Date Author Description
1.0 7/3/2009 1. Created this procedure.
NOTES:
Automatically available Auto Replace Keywords:
Object Name: proc_MDM_InsertCntryDetails
Sysdate: 7/3/2009
Date and Time: 7/3/2009, 7:11:20 PM, and 7/3/2009 7:11:20 PM
Username: (set in TOAD Options, Procedure Editor)
Table Name: (set in the "New PL/SQL Object" dialog)
BEGIN
SELECT COUNT(*) INTO ifExist FROM MDM_COUNTRY_MASTER;
IF ifExist = 0 THEN
SELECT 1 INTO nMaxMDMCode FROM DUAL;
ELSE
SELECT MAX(MDM_CODE)+1 INTO nMaxMDMCode FROM MDM_COUNTRY_MASTER;
END IF;
IF Action='add' THEN
INSERT INTO MDM_COUNTRY_MASTER(MDM_CODE,MDM_MASTER_CODE,MDM_DESCRIPTION,MDM_USER,MDM_EXIST,MDM_STATUS,MDM_ACTION,DAT_INSERT_DATE,DAT_INSERTED_BY)
     VALUES(nMaxMDMCode,CntryMasterCode,CntryName,MDMUser,Exist,status,Action,SYSDATE,Inserted_By);
strSQLXGen := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || XGenAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || nMaxMDMCode || ',' || '''' || 'XGen' || '''' || ',1,' || XGenAttValues || ',' || '''' || Inserted_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLXGen;
strSQLMirus := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || MirusAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || nMaxMDMCode || ',' || '''' || 'Mirus' || '''' || ',2,' || MirusAttValues || ',' || '''' || Inserted_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLMirus;
strSQLGenisys := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || GenisysAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || nMaxMDMCode || ',' || '''' || 'Genisys' || '''' || ',3,' || GenisysAttValues || ',' || '''' || Inserted_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLGenisys;
ELSE
UPDATE MDM_COUNTRY_MASTER
SET MDM_DESCRIPTION=CntryName,DAT_MODIFIED_BY=Modified_By,DAT_MODIFY_DATE=SYSDATE,
MDM_USER=MDMUser,MDM_ACTION=Action,MDM_STATUS=status,MDM_EXIST=Exist WHERE MDM_CODE=Mdm_Code;
SELECT COUNT(*) INTO ifExist FROM MDM_COUNTRY_MAPPING WHERE SYSTEM_CODE=1 AND MDM_CODE=Mdm_Code ;
IF ifExist = 0 THEN
strSQLXGen := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || XGenAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || Mdm_Code || ',' || '''' || 'XGen' || '''' || ',1,' || XGenAttValues || ',' || '''' || Modified_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLXGen ;
ELSE
strSQLXGen := 'UPDATE MDM_COUNTRY_MAPPING SET ' || XGenModify || ',DAT_MODIFY_DATE=SYSDATE,DAT_MODIFIED_BY=' || '''' || Modified_By || '''' || ' WHERE MDM_CODE=' || Mdm_Code || ' and SYSTEM_CODE=1' ;
EXECUTE IMMEDIATE strSQLXGen ;
END IF;
SELECT COUNT(*) INTO ifExist FROM MDM_COUNTRY_MAPPING WHERE SYSTEM_CODE=2 AND MDM_CODE=Mdm_Code ;
IF ifExist = 0 THEN
strSQLMirus := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || MirusAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || Mdm_Code || ',' || '''' || 'Mirus' || '''' || ',2,' || MirusAttValues || ',' || '''' || Modified_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLMirus ;
ELSE
strSQLMirus := 'UPDATE MDM_COUNTRY_MAPPING SET ' || MirusModify || ',DAT_MODIFY_DATE=SYSDATE,DAT_MODIFIED_BY=' || '''' || Modified_By || '''' || ' WHERE MDM_CODE=' || Mdm_Code || ' and SYSTEM_CODE=2' ;
EXECUTE IMMEDIATE strSQLMirus ;
END IF;
SELECT COUNT(*) INTO ifExist FROM MDM_COUNTRY_MAPPING WHERE SYSTEM_CODE=3 AND MDM_CODE=Mdm_Code;
IF ifExist = 0 THEN
strSQLGenisys := 'INSERT INTO MDM_COUNTRY_MAPPING(MDM_CODE,SYSTEM_NAME,SYSTEM_CODE,' || GenisysAttNames || ',DAT_INSERTED_BY,DAT_INSERT_DATE) ' ||
'VALUES(' || Mdm_Code || ',' || '''' || 'Genisys' || '''' || ',3,' || GenisysAttValues || ',' || '''' || Modified_By || '''' || ',SYSDATE)';
EXECUTE IMMEDIATE strSQLGenisys ;
ELSE
strSQLGenisys := 'UPDATE MDM_COUNTRY_MAPPING SET ' || GenisysModify || ',DAT_MODIFY_DATE=SYSDATE,DAT_MODIFIED_BY=' || '''' || Modified_By || '''' || ' WHERE MDM_CODE=' || Mdm_Code || ' and SYSTEM_CODE=3' ;
EXECUTE IMMEDIATE strSQLGenisys ;
END IF;
END IF;
EXCEPTION
WHEN NO_DATA_FOUND THEN
NULL;
WHEN OTHERS THEN
-- Consider logging the error and then re-raise
RAISE;
END proc_MDM_InsertCntryDetails;
Thanks

Answer 1

It might be helpful to search this forum and google for PL/SQL (variables, stored procs, etc) naming standards. There are quite a few out there and you can choose one that works for you.
As an example, a lot of standards adopt naming prefixes, ie v_ for VARCHAR variable, n_ for NUMBER variable, pv_ for paramater VARCHAR, etc.