What exactly is wrong with result of the query?

>
>No, that didn't work. I seem to have cracked it with:
>

>...
>  LEFT JOIN RF1 ;
>    On	NET.Operator  == RF1.Operator ;
>    and (    NET.Route == RF1.ERoute ;
>      	 or EMPTY( RF1.ERoute) ) ;
>...
>

>
>>>Sorry Sergey, I don't understand. I'm not intending to do "strange experiments". Your reply is very vague. I told you originally had that clause in, and got wrong results, and this was before I was advised to LEFT JOIN.
>>>
>>>Is there a solution to this or is the whole thread too hard to understand?
>>Try
>>

>>SELECT DISTINCT NET.Operator, NET.Route, NET.Start_Date, NET.End_Date, NET.RorF, NET.Passengers, ;
>>	IIF( NET.Route == NET.Mcl_Rte, "    ", NET.Mcl_Rte) as ContrNum, NET.Family, ;
>>	0000000 AS CurrPass, 0000000 AS PrevPass, op.Desc as OpDesc, ;
>>	NVL(RF1.ServType, "?") as ServeType ;	
>>  FROM NotETM NET ;
>>    JOIN Operator op ;
>>      On NET.Operator == op.Code ;
>>    LEFT JOIN RF1 ;
>>      On  NET.Operator == RF1.Operator ;
>>      and NET.Route    == RF1.ERoute ;
>>  WHERE (	 (	m.ldStartCurr BETWEEN NET.Start_date AND NET.End_date) ; ...
>>