Issue with line item (table control)

Hi, im currently stuck at line item insert. Upon saving, it is not saving the line item

Im using following select statement to get line item. No issue when i created header and line item from database table. The issue occured when i tried to do save changes (function code: sve) for the insert. Correct me if theres something wrong with my select statement

MODULE FETCH_DATA OUTPUT.

  SELECT EBELN LIFNR EKORG EKGRP BUKRS WAERS ZTERM ZDESC FROM ZEKKO_03
INTO CORRESPONDING FIELDS OF TABLE GT_ZEKKO
WHERE EBELN = GWA_ZEKKO-EBELN.

  SELECT SINGLE EBELN LIFNR EKORG EKGRP BUKRS WAERS ZTERM ZDESC FROM ZEKKO_03
    INTO CORRESPONDING FIELDS OF GWA_ZEKKO
    WHERE EBELN = GWA_ZEKKO-EBELN.

  READ TABLE GT_ZEKKO INTO GWA_ZEKKO INDEX SY-TABIX.


  SELECT EBELP MATNR WERKS LGORT MENGE MEINS
    INTO CORRESPONDING FIELDS OF TABLE GT_ZEKPO FROM ZEKPO_03
     WHERE EBELN = GWA_ZEKKO-EBELN.

    MOVE-CORRESPONDING gwa_zekpo TO zekpo_03.

This is the insert i used. Im trying to look for insert <dbtab> with where clause or with index <table control>-current_line seems like theres no such statement (correct me if they exist).

 WHEN 'SVE'.

      CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'
        EXPORTING
          INPUT  = GWA_ZEKKO-EBELN
        IMPORTING
          OUTPUT = GWA_ZEKKO-EBELN.

      IF GV_CREATE EQ 'X'.

        INSERT ZEKKO_03 FROM GWA_ZEKKO .


        READ TABLE gt_zekpo INDEX tc_zekpo-current_line INTO gwa_zekpo.
        insert INTO zekpo_03 VALUES gwa_zekpo .            

        CALL FUNCTION 'NUMBER_GET_NEXT'
          EXPORTING
            NR_RANGE_NR = GV_RANGE
            OBJECT      = 'ZEBELN_03'
          IMPORTING
            NUMBER      = GWA_ZEKKO-EBELN.     

      ENDIF.

      IF SY-SUBRC = 0.
        COMMIT WORK.
        MESSAGE 'Entry created' TYPE 'S'.
      ELSE.
        MESSAGE 'Create entry failed' TYPE 'E'.

      ENDIF.

      IF GV_EDIT EQ 'X' .

        UPDATE ZEKKO_03 SET
       EKGRP = GWA_ZEKKO-EKGRP
       EKORG = GWA_ZEKKO-EKORG
       BUKRS = GWA_ZEKKO-BUKRS
       LIFNR = GWA_ZEKKO-LIFNR
       WAERS = GWA_ZEKKO-WAERS
       ZTERM = GWA_ZEKKO-ZTERM
       ZDESC = GWA_ZEKKO-ZDESC
       WHERE EBELN = GWA_ZEKKO-EBELN.


        UPDATE ZEKPO_03 SET
       EBELP = GWA_ZEKPO-EBELP
       MATNR = GWA_ZEKPO-MATNR
       WERKS = GWA_ZEKPO-WERKS
       LGORT = GWA_ZEKPO-LGORT
       MENGE = GWA_ZEKPO-MENGE
       MEINS = GWA_ZEKPO-MEINS
       WHERE EBELN = GWA_ZEKKO-EBELN.
        COMMIT WORK.

      ENDIF.

  ENDCASE.

  CLEAR GT_ZEKKO.
  CLEAR GT_ZEKPO.

ENDMODULE.