IBMi (AS400) fans only : how to read a flat file with sql embedded

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RPG program logic cycle
#IBMiSample

It often happens that you have to read all the records of a file.
Years ago I would have used the RPG cycle defining the Input/Primary file.

Today, with the introduction of embedded SQL, I would do this:


First of all I create a file, then I manually write some records.


to create a file I write this SQL source:

IPFLSQL.SQL

--
--  RUNSQLSTM SRCFILE(myLib/MySouceFile) SRCMBR(IPFLSQL)
--
--  Generazione tabella
CREATE OR REPLACE TABLE myLib/IPFLI00F (
IIFANN CHARACTER(1) NOT NULL WITH DEFAULT,
IITEXT CHARACTER(25) NOT NULL WITH DEFAULT
)
RCDFMT IPFLI
; 

Run IPFLSQL.SQL with
RUNSQLSTM SRCFILE(myLib/MySouceFile) SRCMBR(IPFLSQL) to create the file IPFLI00F.

Then populate IPFLI00F with some records. No matter what you type, just a few records are enough.

Then compile and run 

IPFL01.SQLRPGLE

**free
// *******************************************************
// *  How to read an entire file from the beginning      *
// *******************************************************
ctl-opt option(*nodebugio:*srcstmt:*nounref);
 
// IPFLI00F This file is readed from the beginning
 
dcl-ds RecordDsC1;
  rDsIIFANN char( 1);
  rDsIITEXT char(25);
end-ds;
 
exec sql set option Commit = *None;
exec sql set option SRTSEQ = *LANGIDSHR;
exec sql set option CLOSQLCSR = *ENDMOD;
// preapre the data recordset
exec sql declare C1 cursor for
  select
         IIFANN,
         IITEXT
  from IPFLI00F
  where
      IIFANN <> 'A'
  order by IITEXT
  for read only;
 
// *******************************************************
// * PGM start                                           *
// *******************************************************
 
exec sql close C1;
exec sql open C1;
 
dow sqlCode = 0;
  exec sql fetch C1 into :RecordDsC1;
  if sqlcode = 0;
    // ... do something
  endif;
enddo;
exec sql close C1;
*inlr = *on; 
 


Type call ipfl01 (maybe under DEBUG) and check the program.

I use this template whenever I need to read an entire file.

Instead of // ... do something try
dsply %subst(rDsIITEXT:1:10);

That's it.

I appreciate all the comments made on this blog.

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