HSQLDB 中的 PARTITION BY 替代方案

我想触发中建议的查询https://stackoverflow.com/a/3800572/2968357 https://stackoverflow.com/a/3800572/2968357在 HSQLDB 数据库上使用select * such as

WITH tmpTable AS (
SELECT p.* ,
        ROW_NUMBER()  OVER(PARTITION BY p.groupColumn order by p.groupColumn desc) AS rowCount
  FROM sourceTable p) SELECT * FROM  tmpTable WHERE tmpTable.rowCount = 1

但出现以下错误：

Caused by: org.hsqldb.HsqlException: unexpected token: PARTITION required: )

meaning 分区依据不支持。

我对 HSQLDB 的特定查询有解决方法吗？

HSQLDB 支持该答案中的第二个查询。如果您使用 HSQLDB DatabaseManager 和insert test data从它的options菜单中，您将获得填充有数据且适合此类查询的表。

SELECT MIN(x.id),  
     x.customerID, 
     x.total
FROM INVOICE x
JOIN (SELECT p.customerID,
             MAX(total) AS max_total
        FROM INVOICE p
    GROUP BY p.customerID) y ON y.customerID = x.customerID
                          AND y.max_total = x.total
GROUP BY x.customerID, x.total

但是当你想从两个表中进行选择时，HSQLDB 中有一个有趣的替代方案，它的性能非常好：

SELECT INV.* FROM CUSTOMER, 
LATERAL (SELECT ID, CUSTOMERID, CUSTOMER.FIRSTNAME, TOTAL 
FROM INVOICE  
WHERE CUSTOMERID = CUSTOMER.ID 
ORDER BY TOTAL, ID LIMIT 1) INV

该查询返回如下结果：

ID CUSTOMERID FIRSTNAME TOTAL   
-- ---------- --------- ------- 
1  0          Laura     2700.90 
36 1          Robert    4761.60 
27 3          Michael   3420.30 
12 4          Bill      3867.30