Re: Parameter passing CL to RPGLE

On 07-Oct-2016 13:05 -0500, Peter Dow wrote:

One final note - I didn't use Charles Wilt's simple method

<quote>
But why wouldn't you just use
d OB0050AN pi
d @RETURNCODE 2a
d @CALLER 10a
d PARMS likeds(@PARMS)
</quote>

because on v5r4 I can't define the template data structure with the
TEMPLATE keyword, which means it had to be QUALIFIED, and the SQL
pre-compiler can't handle qualified names as host variables, e.g.
for the following SQL

UPDATE myTable SET myColumn = :@PARMS.@MODE WHERE ...

the pre-compiler gives two errors, variable @PARMS undefined or
unusable and variable @MODE undefined or unusable.

I'm not sure if having the TEMPLATE keyword available would have
allowed me to use unqualified subfield names or not.

You can effect nearly identical to what TEMPLATE provides, using BASED, as shown here. Note that the QUALIFIED keyword is *not* required to be specified; although unqualified references will be problematic if the basing pointer is not set correctly; oddly, I do not get a MCH3601 on v6r1 [but I do on v5r3, and msg CPF8E17 when EVAL @MODE] when the basing pointer is initialized to *NULL as shown, and instead get INCORROUT UNPRED (UR) results -- but the code shown here sets the pointer to the address of the by-reference-pointer *immediately* upon entry:

d ptrToData s * inz(*NULL)
d @PARMS e DS extname(OB0050PR)
d based(ptrToData)

d OB0050AN pi
d @RETURNCODE 2A
d @CALLER 10A
d PARMS likeds(@PARMS)
d c111 s 111A

/free
ptrToData = %addr(PARMS) ;

// The following, if un-commented, are function equivalents:
// if parms.@mode = 'B' ;
// if @MODE = 'B' ;

Thus, for the same reason those two predicates are the /same/, the SQL can be written as shown here, thus avoiding a qualified name that would prevent the pre-compiler from functioning as desired:

UPDATE myTable SET myColumn = :@MODE WHERE ...