Inner Join to retrieve the Material Valuation Class in sap abap programming

Inner Join to retrieve the Material Valuation Class pointing to
* which General Ledger.
*
* Based on transaction OBYC - Inventory Posting - BSX
*
* If you use inner join to read data from several logically
* connected tables instead of nested Select statements.
* It will reduce your network load.
*
* Written by : SAP Basis, ABAP Programming and Other IMG Stuff
*
REPORT ZVALGL.

TABLES: MARA,   "General Material Data
      MAKT,   "Material Descriptions
      MBEW,   "Material Valuation
      SKAT,   "G/L Account Master Record
      T025T,  "Valuation Class Descriptions
      T030.   "Standard Accounts Table

DATA: BEGIN OF WA,
      BKLAS  TYPE MBEW-BKLAS,
      BKBEZ  TYPE T025T-BKBEZ,
      MTART  TYPE MARA-MTART,
      MATNR  TYPE MARA-MATNR,
      MAKTX  TYPE MAKT-MAKTX,
    END OF WA,
    ITAB LIKE SORTED TABLE OF WA
              WITH NON-UNIQUE KEY BKLAS MATNR.

SELECT-OPTIONS: PLANT    FOR MBEW-BWKEY MEMORY ID PLT,
              MATLTYPE FOR MARA-MTART MEMORY ID TYP,
              MATERIAL FOR MBEW-MATNR MEMORY ID MAT,
              CHARTACC FOR T030-KTOPL MEMORY ID KTO.

SELECT P~BKLAS
     F~MATNR F~MTART
     G~MAKTX
     T~BKBEZ
  INTO CORRESPONDING FIELDS OF TABLE ITAB
  FROM ( ( ( ( MBEW AS P
       INNER JOIN MARA  AS F ON P~MATNR  = F~MATNR )
       INNER JOIN MAKT  AS G ON P~MATNR  = G~MATNR )
       INNER JOIN T025T AS T ON P~BKLAS  = T~BKLAS ) )
  WHERE P~BWKEY IN PLANT
    AND F~MTART IN MATLTYPE
    AND P~MATNR IN MATERIAL
    AND G~SPRAS =  'E'.

LOOP AT ITAB INTO WA.
  CLEAR: T030, SKAT.
  SELECT SINGLE * FROM T030 WHERE BKLAS = WA-BKLAS
                              AND KTOSL = 'BSX'.
  SELECT SINGLE * FROM SKAT WHERE SAKNR = T030-KONTS
                              AND SPRAS = 'E'.
  WRITE: / WA, T030-KONTS, SKAT-TXT20.
ENDLOOP.