How To Use "For All Entries In Itab"

How To Use "For All Entries In Itab"
- Usually use for Sql Select Statement,it is for search condition in a list or a internal table.
For Instance:
-Internal Table: ITAB_A
Carrid Connid
LH 2415
SQ 0026
LH 0400

-Sql Section
Select * from sfligh into wa-sfligh
For All Entries In ITAB_A
where Carrid = ITAB_A-Carrid
and Connid = ITAB_A-Connid
and Fldate = '20010228'
.....
EndSelect.

-The Statement has the same effect as:
Select Distinct * from sflight into wa-sfligh
where Carrid = 'LH'
And Connid ='2415'
And fldate = '20010228' or
( Carrid = 'SQ'
And Connid ='0026'
And fldate = '20010228') Or
(Carrid = 'LH'
And Connid ='0400'
And fldate = '20010228')
...
EndSelect.