SQL with parameters - need to PREPARE and 'OPEN ... USING'?

We are on IBM I V7R1.

I have a question:

When using a cursor in SQL with variable values do you NEED to use a prepare
statement with a variable marker, (a question mark (?)), and then execute ‘OPEN
… USING’ with the variable values?

I thought this sort of construct was required when the selection variables
values were ... well, variable.

I have come across code that I thought would not work….

An SQL declare statement loaded in the *INZSR subroutine….

C/EXEC SQL
C+
C+ declare @cursorDft999 Cursor for
C+ Select zbsrtp from zbsrcefe
C+ Where zbcmp# = :zbcmp# and zbprcd = :zbprcd
C+ and zbtrnm = :zbtrnm
C+ and zbsrcd like '999%'
C+ Order by zbcrcd desc
C+
C/END-EXEC

And then in a seperate subroutine …

begsr $get_zbsrtp;

C/EXEC SQL
C+ OPEN @cursorDft999
C/END-EXEC

C/EXEC SQL
C+ FETCH NEXT FROM @cursorDft999
C+ into :srtp
C/END-EXEC

If Sqlcod = *Zeros;
zbsrtp = srtp;
Endif;

C/EXEC SQL
C+ Close @cursorDft999
C/END-EXEC

endsr;

At each execution of the subroutine the values of ZBCMP#, ZBPRCD, and ZBTRNM
are different depending on the data being processed.

I would have sworn this was not going to work as coded above. I thought one
needed to use the ‘OPEN …. USING’ syntax.

Any comments appreciated.

(Feeling a bit dim-witted today)

Paul