偶然发现FMTDTA（IBM i）

Question

I stumbled on some FMTDTA which seem to be a query/sort language that predates SQL in an old RPG System. I am trying to unravel it's usage.

Example:

Physical file layout:

ORNO         S      9 0     1     9 Order No       
ORCSTNO      A     10      10    19 Custno        
ORDAT        S      6 0    20    25 Order Date     
ORAMT        S     12 2    26    37 Order Amt  

Sort Criteria in PF source member ORDSRT:

HSORTR    25A                      Keyfields are 25 characters long - Sort Ascending
FNC  20  25                        KEY 1: ORDER DATE              
FNC   1   9                        KEY 2: ORDERNO                 
FNC  10  19                        KEY 3:  CUST NO                 
FDC   1  37                        Take whole record (1-37)       

Sort command

FMTDTA INFILE((MYLIB/ORDHED)) OUTFILE(QTEMP/ORDHED)          
SRCFILE(MYLIB/MYSRC) SRCMBR(ORDSRT) OPTION(*NOPRT)       

Result:

successfully sorts by DATE/ORD#/CUST#

However, there are a few other lines in FMTSRC that I am not sure of their purpose. Examples:

FOU 
FOC
FNU
O C   1   1EQCD                    CANCELLED  
I C   8   8EQCB                    CREDIT NOTE
O C   1   1EQCX                    OMIT CANCELLED

Answer 1

Here's what those six lines mean:

FOU

Col 6: F means it's a Field statement

Col 7: O means the field is an opposite control field

Col 8: U means the field contains signed decimal data in zoned format

FOC

Col 6: F means it's a Field statement

Col 7: O means the field is an opposite control field

Col 8: C means the field contains character data

FNU

Col 6: F means it's a Field statement

Col 7: N means the field is a normal control field

Col 8: U means the field contains signed decimal data in zoned format

O C   1   1EQCD                    CANCELLED

Col 6: O means OMIT

Col 8: C means Factor 1 and Factor 2 must contain character data

Col 9: 1 is the starting position of Factor 1

Col 13: 1 is the ending position of Factor 1

Col 17: EQ means Factor 1 must equal Factor 2

Col 19: C means Factor 2 is constant

Col 20: D is the constant or keyword against which Factor 1 is compared

Col 40: CANCELLED is a comment

I C   8   8EQCB                    CREDIT NOTE

Col 6: I means INCLUDE

Col 8: C means Factor 1 and Factor 2 must contain character data

Col 9: 8 is the starting position of Factor 1

Col 13: 8 is the ending position of Factor 1

Col 17: EQ means Factor 1 must equal Factor 2

Col 19: C means Factor 2 is constant

Col 20: B is the constant or keyword against which Factor 1 is compared

Col 40: CREDIT NOTE is a comment

O C   1   1EQCX                    OMIT CANCELLED

Col 6: O means OMIT

Col 8: C means Factor 1 and Factor 2 must contain character data

Col 9: 1 is the starting position of Factor 1

Col 13: 1 is the ending position of Factor 1

Col 17: EQ means Factor 1 must equal Factor 2

Col 19: C means Factor 2 is constant

Col 20: X is the constant or keyword against which Factor 1 is compared

Col 40: OMIT CANCELLED is a comment

Reference

Answer 2

More on the stumbling. In SEU on the control line. IP? and you can bring up a prompt line for sort Below I have RF F lines in the sort and I press f1 on the start position. it won't auto prompt for me today when I press f4 or type something in wrong it won't find it but you can press f1 help when the prompt is up. Then you translate it to something a little more modern.