简化查询字符串通过重新使用MYSQL

Question

的导出字段列名

我们仍然可以通过使用派生列简化这个查询是另一个程序的输入

$query = "SELECT table1.id, 
     COUNT(DISTINCT arr1.element) AS Arr1, 
     COUNT(DISTINCT arr2.element) AS Arr2, 
     COUNT(DISTINCT arr1.element) + 
     COUNT(DISTINCT arr2.element) AS tot, 
(COUNT(DISTINCT arr1.element)/(COUNT(DISTINCT arr1.element)+COUNT(DISTINCT arr2.element)))*col3 AS c31, 
(COUNT(DISTINCT arr2.element)/(COUNT(DISTINCT arr1.element)+COUNT(DISTINCT arr2.element)))*col3 AS c32 
FROM table1 
WHERE col2 = 'x'" 

像这样

$query = "SELECT table1.id, 
     COUNT(DISTINCT arr1.element) AS Arr1, 
     COUNT(DISTINCT arr2.element) AS Arr2, 
     COUNT(DISTINCT arr1.element) + 
     COUNT(DISTINCT arr2.element) AS tot, 
     (Arr1/tot)*col3 AS c31, 
     (Arr2/tot)*col3 AS c32 
FROM table1 
WHERE col2 = 'x'" 

感谢

Answer 1

您可以试试这个：

$query = " 
SELECT tab.id, tab.Arr1, tab.Arr2, tab.tot, (tab.Arr1/tab.tot) as c31, (tab.Arr2/tab.tot) as c32 
from (
SELECT table1.id, 
     COUNT(DISTINCT arr1.element) AS Arr1, 
     COUNT(DISTINCT arr2.element) AS Arr2, 
     COUNT(DISTINCT arr1.element) + 
     COUNT(DISTINCT arr2.element) AS tot 
FROM table1 
WHERE col2 = 'x' 
) as 'tab' " 

Answer 2

试试这个：

SELECT id, Arr1, Arr2, (Arr1 + Arr2) tot, ((Arr1/(Arr1 + Arr2)) * col3) c31, ((Arr2/(Arr1 + Arr2)) * col3) c32 
FROM (SELECT table1.id, COUNT(DISTINCT arr1.element) AS Arr1, COUNT(DISTINCT arr2.element) AS Arr2, col3 
FROM table1 WHERE col2 = 'x') AS A