Question

嗨，我有2张桌子。我想列出

table1中存在的所有记录表2
table2中的所有记录，其中table1中没有where条件

第二个条件中table1将返回空行，但我无法使查询正常工作。它只返回空行

SELECT 
    A.CLMSRNO,A.CLMPLANO,A.GENCURRCODE,A.CLMNETLOSSAMT,
    A.CLMLOSSAMT,A.CLMCLAIMPRCLLOSSSHARE
FROM 
    PAKRE.CLMCLMENTRY A 
RIGHT OUTER JOIN (
    SELECT 
        B.CLMSRNO,B.UWADVICETYPE,B.UWADVICENO,B.UWADVPREMCURRCODE,
        B.GENSUBBUSICLASS,B.UWADVICENET,B.UWADVICEKIND,B.UWADVYEAR,
        B.UWADVQTR,B.ISMANUAL,B.UWCLMNOREFNO 
    FROM
        PAKRE.UWADVICE B 
    WHERE
        B.ISMANUAL=1
) r
ON a.CLMSRNO=r.CLMSRNO

ORDER BY 
    A.CLMSRNO DESC;

Answer 1

您使用的是哪种操作系统？

Table aliases are case sensistive on some platforms，这就是您的加入条件ON a.CLMSRNO=r.CLMSRNO失败的原因。

尝试A.CLMSRNO=r.CLMSRNO并查看是否有效

Answer 2

我不理解你的第一次尝试，但我认为这基本上是你所需要的：

SELECT *
FROM TABLE1
INNER JOIN TABLE2
    ON joincondition

UNION ALL

SELECT *
FROM TABLE2
LEFT JOIN TABLE1
    ON joincondition
    AND TABLE1.wherecondition
WHERE TABLE1.somejoincolumn IS NULL

Answer 3

我认为您可能希望删除子查询并将其列放入主查询中，例如

SELECT A.CLMSRNO, A.CLMPLANO, A.GENCURRCODE, A.CLMNETLOSSAMT, 
       A.CLMLOSSAMT, A.CLMCLAIMPRCLLOSSSHARE,  
       B.CLMSRNO, B.UWADVICETYPE, B.UWADVICENO, B.UWADVPREMCURRCODE, 
       B.GENSUBBUSICLASS, B.UWADVICENET, B.UWADVICEKIND, B.UWADVYEAR, 
       B.UWADVQTR, B.ISMANUAL, B.UWCLMNOREFNO     
  FROM PAKRE.CLMCLMENTRY A
       RIGHT OUTER JOIN PAKRE.UWADVICE B 
          ON A.CLMSRNO = B.CLMSRNO
 WHERE B.ISMANUAL = 1
 ORDER 
    BY A.CLMSRNO DESC;

外部联接返回Nulls

3 个答案: