將UPDATE語句轉換爲SELECT語句

Question

以下語句更新名爲'test'的表中的列。

UPDATE test AS t 
INNER JOIN test AS q ON(
    q.ptime = t.ptime 
) 
SET t.slope_Percentile =(
    (
     SELECT 
      count(*) 
     FROM 
      (
       SELECT 
        * 
       FROM 
        test 
      )AS t1 
     WHERE 
      t1.slope < t.slope 
    )* 100 /(
     SELECT 
      count(*) 
     FROM 
      (
       SELECT 
        * 
       FROM 
        test 
      ) AS tz 
    ) 
); 

不是更新該列的我想收到的SELECT語句給每個行的讀數（如果它是一個UPDATE語句將被更新）。

的更多信息（如果需要）對錶的性質和代碼的目的是在這裏： Efficient assignment of percentile/rank in MYSQL

Answer 1

SELECT t.ptime, 
( 
    ( 
     SELECT 
      count(*) 
     FROM 
      ( 
       SELECT 
        * 
       FROM 
        test 
      )AS t1 
     WHERE 
      t1.slope < t.slope 
    )* 100 /( 
     SELECT 
      count(*) 
     FROM 
      ( 
       SELECT 
        * 
       FROM 
        test 
      ) AS tz 
    ) 
) AS slope_Percentile 
FROM test AS t 
--INNER JOIN test AS q ON 
--q.ptime = t.ptime 

Answer 2

這個怎麼樣？

SELECT *, (
    (SELECT count(*) 
    FROM test AS t1 
    WHERE t1.slope < t.slope) * 100/
    (SELECT count(*) 
    FROM test as tz)) as newvalue 
FROM test AS t;