将 NOT IN 查询转换为 LEFT JOIN

Question

为了适应 Netezza 数据库，我需要转换休闲查询（因为 Netezza 不支持 NOT IN(SUBQUERY)）：

UPDATE table1 t1 SET t1.deal_type=t2.deal_type 
FROM  table2 t2
WHERE t1.id_col=t2.id_col 
AND t1.price=t2.price
AND t1.id_col2=t2.id_col2
AND t2.price NOT IN (
  SELECT st1.price
  FROM table1 st1, table2 st2
  WHERE st1.id_col=st2.id_col 
  AND st1.price=st2.price
  AND st1.id_col2=st2.id_col2
  AND st1.id_col=t1.id_col
  AND t2.deal_type=st2.deal_type
  GROUP BY st1.id_col, st1.price, st1.id_col2, st2.deal_type
  HAVING COUNT (*)>1);

我尝试使用 LEFT JOIN，但没有返回所有记录：

UPDATE table1 t1 SET t1.deal_type = t2.deal_type
FROM table2 t2 
LEFT JOIN 
   (SELECT st1.price, st1.id_col, st2.deal_type
   FROM table1 st1, table2 st2
   WHERE st1.id_col=st2.id_col 
   AND st1.price=st2.price
   AND st1.id_col2=st2.id_col2
   GROUP BY st1.id_col, st1.price, st1.id_col2, st2.deal_type
   HAVING COUNT (*)>1) subq ON (subq.id_col=t1.id_col
   AND t2.deal_type=subq.deal_type)
WHERE 
 t1.id_col=t2.id_col 
 AND t1.price=t2.price
 AND t1.id_col2=t2.id_col2
 subq.price is null

任何错误的建议。 NETEZZA

不支持 NOT IN 或任何其他工作方式

Answer 1

如果 netezza 支持 EXISTS 并且你的第一个查询在逻辑上是正确的，你能试试这个吗

UPDATE t1 SET t1.deal_type=t2.deal_type 
FROM  table1 t1
INNER JOIN table2 t2 ON t1.id_col=t2.id_col 
    AND t1.price=t2.price
    AND t1.id_col2=t2.id_col2
LEFT JOIN ( SELECT st1.id_col
        FROM table1 st1
        INNER JOIN table2 st2 ON st1.id_col=st2.id_col 
            AND st1.price=st2.price
            AND st1.id_col2=st2.id_col2
            AND t2.deal_type=st2.deal_type
        GROUP BY st1.id_col, st1.price, st1.id_col2, st2.deal_type
        HAVING COUNT (*)>1) i ON i.id_col=t1.id_col
WHERE i.id_col IS NULL

Answer 2

我想你忘了将价格添加到 Left Join 条件中。

如果此 id&type 有重复但价格不同， NOT-IN 条件将通过，但 Left-Join (IS NULL) 条件将失败

只是改变

ON (subq.id_col=t1.id_col
   AND t2.deal_type=subq.deal_type)

至

ON (subq.id_col=t1.id_col
  AND t2.deal_type=subq.deal_type)
  AND subq.price=t2.price)

将 NOT IN 查询转换为 LEFT JOIN

Convert NOT IN query to LEFT JOIN

sql

left-join

netezza