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;      ...
A dairy of my work.Just links to the full artices on i-programmer.info
 
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