Oracle 到 PostgreSQL

Question

有人可以告诉我如何在 PostgreSQL 中转换以下 Oracle SQL 语句吗？ 我不明白...

 SELECT 
     MAX(TKI1.USER_ID)
     KEEP(DENSE_RANK LAST ORDER BY TKI1.UPD_DATE NULLS FIRST)
     OVER(PARTITION BY TKI1.NUMBER) AS  USER_ID         
 FROM
    USER_TABLE TKI1;

Answer 1

您可以使用：

SELECT MAX(CASE WHEN rnk = 1 THEN user_id END) OVER (PARTITION BY NUMBER)
         AS user_id
FROM   (
  SELECT user_id,
         NUMBER,
         RANK() OVER (PARTITION BY NUMBER ORDER BY UPD_DATE DESC NULLS LAST)
           AS rnk
  FROM   user_table
) t