轉換Oracle查詢的到Teradata的查詢

Question

如何將此轉換下面的查詢等效teradate查詢。我嘗試過，但結果變化很大。

select il.domainN as listname, il.SourceID, ns.sourcename, cbo.customerid, cu.username, hv.domainN as HTname 
, nvl((select 1 
     from mydb.customerPP cpp 
     where cbo.customerid = cpp.customerid 
      and NOT EXISTS (select 1 from mydb.customerPI cpt where cpp.customerid = cpt.customerid) 
      and trunc(cpp.startdate) <= sysdate 
     group by cpp.customerid),0) as BBID 
from mydb.customerBO cbo 
    join mydb.customers cu on cbo.customerid = cu.customerid 
    join mydb.inv il on cbo.domainN = il.domainN 
    join mydb.Sources ns on il.SourceID = ns.SourceID 
    left join mydb2.HT hv on (il.domainN = hv.domainN 
            and hv.sDate+1 >= il.dDate 
            and il.dDate+1 >= hv.sDate) 
where cbo.customerBOID = 1 
    and cu.statusid = 1 
    and il.sourceTID = 2 
    and il.joinbydate >= cbo.cDate 
    and trunc(il.dDate) = trunc(sysdate) 

謝謝。

Answer 1

使用COALESCE代替NVL和比較解釋語句來看看你是否已經離開外連接轉換爲內部連接對Teradata的NVL。