tables: aufk                     "Order master data
           jest,                     "Object status
           tj02t.                   "Status Description

*  Order Status - To Retrieve & Filter
select stat from jest
               where objnr = aufk-objnr  " objnr means object no
                   and stat in ('I0012', 'I0045', 'I0074', 'I0076')
                   and inact ne 'X'        "Flag: Status inactive
               order by stat.

select single * from tj02t
                where istat = jest-stat
                    and spras = 'E'.

Is it possible to run abap program from commnad prompt like DOS on windows or unix command line?

Yes. But in my experience it is not advised, use it as a last resort (because of lack of time or lack of technical expertise to write C or java or .NET code )

    SELECT * FROM KNA1 WHERE KUNNR = GV_KUNNR.
              WINDOW STARTING AT 05 10
              ENDING AT 50 20.
         WRITE: KNA1-KUNNR.
    ENDSELECT.

Program Checks: The system checks ABAP programs statically when you create them and dynamically when they are running.

at selection-screen output.
  loop at screen.                
    if screen-name = 'P_PARM1'. 
      screen-output = 1.         
      modify screen.             
      exit.                      
    endif.                       
  endloop.   

parameters: p_infile like ibipparms-path default 'C:\'.

* Executes the pull-down to search C:\ drive for input file 
at selection-screen on value-request for p_infile. 
  call function 'F4_FILENAME'          "allows user to select path/file 
       exporting 
            program_name  = syst-repid 
            dynpro_number = syst-dynnr 
            field_name    = 'p_infile' 
       importing 
            file_name     = p_infile. 
  if sy-subrc ne 0. 
    write: / 'Error'. 
  endif.

• NOT or NE or <>
• LIKE ‘%pattern’
• IS NULL
• IS NOT NULL
• NOT IN

This version of the SELECT statement was the only way to join tables until SAP release 3.0E.  It is recommended that the SQL JOIN be used.  However, this is an alternate method of joining tables that may be used in some circumstances.  Remember, SQL JOIN doesn’t utilize the SAP internal database buffer.

Custom reports often summarize data extracted from large volume tables.  If the SQL statement used to extract the data from the large volume table is designed to use the table's primary index or a secondary index performance will dramatically.  The developer should check all SQL statements and attempt to conform to the available indexes.