返されたクエリされたMySQL一時テーブルのメジアンを計算する方法

Question

私はメダインを計算する必要がある大きなデータベースからテンポラリテーブルを作成しました。

一時テーブルを作成するためのコードの下

（それは数字で容積の21行を持っている）コードの下

CREATE TEMPORARY TABLE table1 (Select vol from EOD_PRICING where 
`ticker`=16665396 order by `xdate` desc limit 21);  

中央値を計算するが、上記のためにそれを行うにはどのようになっていないが、一時的なテーブル「TABLE1」

を作成しました

SELECT AVG(middle_values) AS 'median' FROM (
SELECT t1.`vol` AS 'middle_values' FROM 
(
    SELECT @row:=@row+1 as `row`, x.`vol` 
    FROM table1 AS x, (SELECT @row:=0) AS r 
    WHERE `ticker`=16665396 order by `xdate` desc limit 21 
    ORDER BY x.`vol` 
) AS t1, 
(
    SELECT COUNT(*) as 'count' 
    FROM table1 x 
    WHERE `ticker`=16665396 order by `xdate` desc limit 21 
) AS t2 
WHERE t1.row >= t2.count/2 and t1.row <= ((t2.count/2) +1)) AS t3; 

私は私の要件のためのUNION ALLでのコードの下に使用している場合、それは You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 17

CREATE TEMPORARY TABLE table1 (Select * from EOD_PRICING where 
`ticker`=16665396 order by `xdate` desc limit 21) 
UNION ALL 
SELECT AVG(middle_values) AS 'median' FROM (
SELECT t1.`vol` AS 'middle_values' FROM 
(
    SELECT @row:=@row+1 as `row`, x.`vol` 
    FROM table1 AS x, (SELECT @row:=0) AS r 
    ORDER BY x.`vol` 
) AS t1, 
(
    SELECT COUNT(*) as 'count' 
    FROM table1 x 
) AS t2 
WHERE t1.row >= t2.count/2 and t1.row <= ((t2.count/2) +1)) AS t3; 

語ります

事前にお手伝いいただきありがとうございます。

Answer 1

解決済み...偶数と奇数の両方について正しい答えを得ました。

SELECT AVG(middle_values) AS 'median' 
FROM (

SELECT t1.`vol` AS 'middle_values' 
FROM (

SELECT @row := @row +1 AS `row` , x.`vol` 
FROM (

SELECT * 
FROM EOD_PRICING 
WHERE `ticker` =16665396 
ORDER BY `xdate` DESC 
LIMIT 22 
) AS x, (

SELECT @row :=0 
) AS r 
ORDER BY x.`vol` 
) AS t1, (

SELECT COUNT(*) AS 'count' 
FROM (

SELECT * 
FROM EOD_PRICING 
WHERE `ticker` =16665396 
ORDER BY `xdate` DESC 
LIMIT 22 
) AS x 
) AS t2 
WHERE t1.row >= t2.count /2 
AND t1.row <= ((
t2.count /2 
) +1) 
) AS t3; 

お返事ありがとうございます。