sql 子查询带有条件怎么改成左连接

SELECT
A.AS_CODE
,A.AS_PACTNAME
,A.AS_STADATE
,A.AS_ENDDATE
,B.AR_SUMTIME
,B.AR_YQTIME
,B.AR_TPTIME
,COUNT(A.AD_CODE)
, COUNT(CASE WHEN C.ED_DOWNSTATE=1
THEN C.EBCOMPANYCODE
END)
, COUNT(CASE WHEN C.ED_DOWNSTATE=0
THEN C.EBCOMPANYCODE
END)
, COUNT(CASE WHEN D.TD_ADCODE IS NOT NULL
THEN TD_ADCODE
END)
FROM AU_SALESPACTVIEW A
LEFT JOIN AU_SALESPACTRES B
ON A.AS_CODE=B.AS_CODE
LEFT JOIN AD_EXECBILLDETAIL C
ON C.EBCOMPANYCODE=A.AD_CODE
LEFT JOIN AU_TASKADLIST D
ON D.TD_ADCODE=A.AD_CODE
AND D.HYOWNER='TEMP'
WHERE APTAS_PACTSORT=1
GROUP BY
A.AS_CODE,A.AS_PACTNAME,A.AS_STADATE,A.AS_ENDDATE,B.AR_SUMTIME,B.AR_YQTIME,B.AR_TPTIME