SAP ABAP - Handling with control tables -

my problem:

i "loop" on table local structure named ls_eban..

and information must follow these instructions:

1. ls_eban-matnr must be in zmd_scmi_st01 ( 1. control table (global) )
2. ls_eban-werks must be in zmd_scmi_st05 ( 2. control table (global) )
3. ls_eban-knttp must be in zmd_scmi_st06 ( 3. control table (global) )

i need selection clear , performant. have one, isn't performant @ all.

my solution:

select st01~matnr st05~werks st06~knttp         zmd_scmi_st01 st01   inner join zmd_scmi_st05 st05   on         st05~werks = ls_eban-werks   inner join zmd_scmi_st06 st06   on         knttp = ls_eban-knttp table   lt_control        st01~matnr = ls_eban-matnr , st01~bedarf = 'x'   ,        st05~bedarf = 'x'. 

i have say, control tables doesn't have relation each other (no primary key , no secondary key).

the first thing should not have select inside loop. instead of

loop @ lt_eban ls_eban.       select .... endloop. 

you should single select.

if lt_eban[] not initial.    select ...      table ...      ...       entries in lt_eban     ... endif. 

there may more inefficiencies corrected if had more info ( mentioned in comment vwegert. instance, no keys on control tables? ) select in loop first thing jumps out @ me.