转换相关的MySQL子查询noncorelated

Question

我需要帮助相关子查询转换成非相关，这是一个查询：

http://sqlfiddle.com/#!2/2a67b/3

感谢意见

Answer 1

我真的很努力工作了什么你的SQL试图摆在首位。

它似乎是在最小和最大秒之间（好的，比最大日期时间多1秒）获得每秒钟的时间，并获得记录的数量。

如果是这样，那么最多〜1000秒应对： -

SELECT ADDDATE(MinCallDate, INTERVAL Sub1.i SECOND) AS aDate, COUNT(*) 
FROM 
(
    SELECT MIN(calldate) AS MinCallDate, MAX(calldate) AS MaxCallDate 
    FROM calls 
)Sub0 
CROSS JOIN 
(
    SELECT units.i + tens.i * 10 + hundreds.i * 100 as i 
    FROM (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) units 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) tens 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) hundreds 
) Sub1 
INNER JOIN 
(
    SELECT calldate, ADDDATE(calldate, INTERVAL billsec SECOND) AS callenddate 
    FROM calls 
) b 
ON DATE_FORMAT(ADDDATE('2013-05-14 09:40:30', INTERVAL Sub1.i SECOND),"%Y%m%d%H%i%s") BETWEEN b.calldate AND b.callenddate 
WHERE ADDDATE(MinCallDate, INTERVAL Sub1.i SECOND) <= MaxCallDate 
AND Sub1.i < TIMESTAMPDIFF(SECOND,'2013-05-14 09:40:30', '2013-05-14 09:41:00') 
GROUP BY aDate 

如果你能提供你正在努力实现我也许能拿出更好的东西什么的非SQL解释。

编辑 - 很简单的计数： -

SELECT Sub1.TimeSecond, COUNT(Sub2.CallSecond) 
FROM 
(
    SELECT ADDDATE('2013-05-14 09:40:30', INTERVAL units.i + tens.i * 10 + hundreds.i * 100 + thousands.i * 1000 SECOND) AS TimeSecond 
    FROM (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) units 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) tens 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) hundreds 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) thousands 
    HAVING TimeSecond BETWEEN '2013-05-14 09:40:30' AND '2013-05-14 09:41:00' 
) Sub1 
LEFT OUTER JOIN 
(
    SELECT ADDDATE(calldate, INTERVAL units.i + tens.i * 10 + hundreds.i * 100 + thousands.i * 1000 SECOND) AS CallSecond 
    FROM calls 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) units 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) tens 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) hundreds 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) thousands 
    WHERE units.i + tens.i * 10 + hundreds.i * 100 + thousands.i * 1000 <= billsec 
) Sub2 
ON Sub1.TimeSecond = Sub2.CallSecond 
GROUP BY Sub1.TimeSecond 

这将应付的范围/手机通话9999秒（易于扩展它更大的范围内，但会使其速度较慢但不能肯定。所有这些都将是有效，因为MySQL不能真正使用索引的任何连接

简单

会是这样，因为它不是每个通话时长中产生，每次： - 。

SELECT Sub1.TimeSecond, COUNT(calls.calldate) 
FROM 
(
    SELECT ADDDATE('2013-05-14 09:40:30', INTERVAL units.i + tens.i * 10 + hundreds.i * 100 + thousands.i * 1000 SECOND) AS TimeSecond 
    FROM (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) units 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) tens 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) hundreds 
    CROSS JOIN (SELECT 0 AS i UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) thousands 
    HAVING TimeSecond BETWEEN '2013-05-14 09:40:30' AND '2013-05-14 09:41:00' 
) Sub1 
LEFT OUTER JOIN calls 
ON Sub1.TimeSecond BETWEEN calls.calldate AND ADDDATE(calls.calldate, INTERVAL calls.billsec SECOND) 
GROUP BY Sub1.TimeSecond 

你可以改变表格的布局吗？如果是这样，为呼叫结束日期时间添加一列可能会有所帮助。