Hi ,
Does this internal table have any fields in common in all the three.
If yes , then loop ls_mat
Declare a type will all the fields and create a structure and internal table with that type (for ex lx_final and lt_final respectively)
Loop at ls_mat into lx_mat.
1.copy all the fields of lx_mat to respective lx_final.
2.read table it_stpo into lx_stpo with key field = lx_mat-field.
3.Copy all fields of lx_stpo to respective lx_final.
4. read table it_mast into lx_mast with key field = lx_mat-field.
5. copy all fields of lx_mast to respective lx_final.
6. now append lx_final to lt_final.
Endloop.
now you can get all values inside lt_final.
Regards,
sivaganesh