Cursor Operation in Netezza - oracle

Question

CREATE OR REPLACE PROCEDURE SP_NEW_PROCEDURE1( )
RETURNS REFTABLE(employees)
LANGUAGE NZPLSQL AS
BEGIN_PROC
DECLARE
l_conditions varchar(1000);
p_rec RECORD;
BEGIN
FOR P_REC IN select empid, mgrid, empname, salary from employees where mgrid = 7
LOOP
l_conditions := 'insert into ' ||
REFTABLENAME ||
' VALUES (' ||
P_REC.EMPID ||
',' ||
P_REC.MGRID ||
',' ||
P_REC.EMPNAME ||
',' ||
P_REC.SALARY ||
' ) ; ' ;
execute immediate l_conditions;
l_conditions := ' ';
END LOOP;
RETURN REFTABLE;
END;
END_PROC;
When I run this:
select SP_NEW_PROCEDURE1()
I get the errors:
ERROR [01000] NOTICE: Error occurred while executing PL/pgSQL function SP_NEW_PROCEDURE1
ERROR [01000] NOTICE: line 24 at execute statement
ERROR [42S22] ERROR: Attribute 'DAN' not found
Can someone help whats wrong ...thanks

Answer 1

This has nothing do with the cursor itself, and everything to do with how you are building your dynamical SQL string.
When building dynamic SQL in a Netezza stored procedure, you can use the quote_ident and quote_literal helper functions to let the system know whether you are passing it a literal, or whether you are passing it an identifier. There is an example in the online documentation here. Essentially all they do is figure out the escaped quotation notation needed.
Since you are trying to put the values stored in the columns of your P_REC record into the VALUES part of an insert statement, you could use quote_literal like this:
CREATE OR REPLACE PROCEDURE SP_NEW_PROCEDURE1( )
RETURNS REFTABLE(employees)
LANGUAGE NZPLSQL AS
BEGIN_PROC
DECLARE
l_conditions varchar(1000);
p_rec RECORD;
BEGIN
FOR P_REC IN select empid, mgrid, empname, salary from employees where mgrid = 7
LOOP
l_conditions := 'insert into ' ||
REFTABLENAME ||
' VALUES (' ||
quote_literal(P_REC.EMPID) ||
',' ||
quote_literal(P_REC.MGRID) ||
',' ||
quote_literal(P_REC.EMPNAME) ||
',' ||
quote_literal(P_REC.SALARY ) ||
' ) ; ' ;
execute immediate l_conditions;
l_conditions := ' ';
END LOOP;
RETURN REFTABLE;
END;
END_PROC;
That being said, using a cursor to loop over records to insert a row one at a time is horribly inefficient in an MPP database like Netezza. Assuming this question is a follow-on from your question about an alternative to a recursive CTE to explore hierarchies, there's nothing wrong with looping in general, but try to avoid doing it record by record. Here is a version that will exploit the MPP nature of the system. For the record, if you are going to return your result set to a REFTABLE, then your only choice is Dynamic SQL.
CREATE OR REPLACE PROCEDURE SP_NEW_PROCEDURE1( )
RETURNS REFTABLE(employees)
LANGUAGE NZPLSQL AS
BEGIN_PROC
DECLARE
l_conditions varchar(1000);
p_rec RECORD;
BEGIN
-- FOR P_REC IN select empid, mgrid, empname, salary from employees where mgrid = 7
-- LOOP
l_conditions := 'insert into ' ||
REFTABLENAME ||
' select empid, mgrid, empname, salary from employees where mgrid = 7 ; ' ;
execute immediate l_conditions;
l_conditions := ' ';
-- END LOOP;
RETURN REFTABLE;
END;
END_PROC;

Answer 2

I suspect that you are building a query that is meant to insert a literal 'DAN' but which does not include the required quote marks, hence it is referencing DAN -- the optimiser is therefore trying to find an attribute of that name.
So the fix is to include the quotation marks when you build the SQL insert statement, or (preferably) to just use static SQL to insert the values instead of execute immediate.
When in doubt, always look at the data, as this would probably have been obvious to you if you inspected the value of l_conditions.