BKARINVT where BKAR_INVT_AMTRM>0 would be all open AR invoices

try this .....
 
SELECT  
BKAR_INVT_CODE,
BKAR_INVT_DATE,
BKAR_INVT_NUM,
BKAR_INVT_AMT,
BKAR_INVT_TYPE,
BKAR_INVT_AMTRM,
BKAR_INVT_MCCOD,
BKARHINV.BKAR_INV_CUSORD,
IF(BKAR_INVT_TYPE = 'I',IF ((CURDATE ( ) - BKAR_INVT_DATE) <= 30, BKAR_INVT_AMTRM, 0 ), 0) 'D_Current',
IF(BKAR_INVT_TYPE = 'I',IF ((CURDATE ( ) - BKAR_INVT_DATE) > 30 AND (CURDATE ( ) - BKAR_INVT_DATE) <= 60, BKAR_INVT_AMTRM, 0 ),0 ) 'D_30',
IF(BKAR_INVT_TYPE = 'I',IF ((CURDATE ( ) - BKAR_INVT_DATE) > 60 AND (CURDATE ( ) - BKAR_INVT_DATE) <= 90, BKAR_INVT_AMTRM, 0 ),0 ) 'D_60',
IF(BKAR_INVT_TYPE = 'I',IF ((CURDATE ( ) - BKAR_INVT_DATE) > 90 AND (CURDATE ( ) - BKAR_INVT_DATE) <= 120, BKAR_INVT_AMTRM, 0 ),0 ) 'D_90',
IF(BKAR_INVT_TYPE = 'I',IF ((CURDATE ( ) - BKAR_INVT_DATE) > 120, BKAR_INVT_AMTRM, 0 ), 0 ) 'D_120',  
(CURDATE ( ) - BKAR_INVT_DATE) AS Total_Days_Late
FROM BKARINVT LEFT JOIN BKARHINV ON BKARINVT.BKAR_INVT_NUM = BKARHINV.BKAR_INV_NUM WHERE BKAR_INVT_AMTRM <> 0;
 
Have fun,
 

 
Kelloggs