SELECT     
	adr_Symbol as Symbol, 
	adr_Nazwa as Kontrahent, 
	ISNULL(rt_Nazwa,'') as [Nazwa rabatu],
	ISNULL(rt_Procent,0) AS [Rabat %]
FROM  dbo.kh__Kontrahent T0
JOIN dbo.adr__Ewid T1 ON T1.adr_IdObiektu = T0.kh_Id
LEFT JOIN dbo.sl_Rabat T2 ON T2.rt_id = T0.kh_IdRabat 
WHERE     (T1.adr_TypAdresu = 1)