4GL's virtues (Part 2) Intergration with SQL

4GL makes code that would be difficult to write purely in SQL easy ,
plus it adds extra capabilities that would not be possible.

The following is a select loop that retrieves the result set
of a SQL query row by row and then manipulates it inside the loop.
Inside the loop you are free to use more SQL queries or 4GL code or mix them both!

For example, you can test conditions using if..then..else statements, assign values to host variables, load a tablefield or update tables in the database!

select   h_c_ylik = c_ylik,
         h_no_seir = no_seir,
         h_ps = ps,
         h_sxolia = sxolia
  from  mlax
  where end_axr='Ο'
  {
  if h_no_seir = '' then
     update mlax m
     set ps = ps + :h_ps
     where end_axr = ''  and
           no_seir = '' and
           c_ylik = :h_c_ylik;
     inquire_ingres (h_rowcount = rowcount,
                     h_errorno=errorno);
     if h_errorno!=0 then 
        rollback;
      callframe err_handler;
     endif;    
     if h_rowcount = 0 then
        insert into mlax
        (c_ylik,no_seir,end_axr,ps,sxolia)
        values
        (:h_c_ylik,'','',:h_ps,:h_sxolia);
        inquire_ingres (h_rowcount = rowcount,
                        h_errorno=errorno);
      if h_errorno!=0 then 
                   rollback;
           callframe err_handler;
               endif;
     endif;       
    else
       insert into mlaxr
       (c_ylik,no_seir,end_axr,ps,sxolia)
       values
       (:h_c_ylik,:h_no_seir,'',:h_ps,:h_sxolia);
       inquire_ingres (h_rowcount = rowcount,
                       h_errorno=errorno);
       if h_errorno!=0 then 
          rollback;
          callframe err_handler;
       endif;
    endif;
  };

There are many situations like this that make evident that 4GL is a rapid development tool