PROBLEMS WITH SAP NETWEAVER (SAP SQL CONNECTOR) TO SAP HANA

[GSGM]

I have some problems with SAP SQL Connector to SAP HANA S/4. 
I'm not able to alias fields, and this cause me problems with left join. 

This is the query that i'm trying: 

SQL
SELECT
U1~UMREZ   AS A1,
U1~UMREN  AS A2,
U2~UMREZ  AS B1
U2~UMREN  AS B2
FROM ZQGCZ AS Z
LEFT JOIN MARM AS U1 ON U1~MATNR = Z~MATNR AND U1~MEINH = Z~MEINS 
LEFT JOIN MARM AS U2 ON U2~MATNR = Z~MATNR AND U2~MEINH='TO';