从两个 SQL Count() 结果计算百分比

Question

我需要计算已完成交易占总交易的百分比（例如，包括进行中交易和已完成交易）。通过浏览网络，我得出了：

SELECT 100 * (SELECT COUNT(transaction_id) from t_transaction_main   
WHERE due_date = '2016-05-16' and (suspend_status !='' OR
close_date != '0-0000-00'))/COUNT(transaction_id) from t_transaction_main as test;

到目前为止它一直有效；然而，虽然最终交易查询符合预期，但实际上我需要将其除以特定日期（此处为 2016-05-16）的交易。但是当我添加一个 WHERE 子句时...

SELECT 100 * (SELECT COUNT(transaction_id) from t_transaction_main   
WHERE due_date = '2016-05-16' and (suspend_status !='' OR
close_date !='0-0000-00'))/COUNT(transaction_id) WHERE due_date = '2016-05-16' from t_transaction_main as test;

它立即停止工作并返回语法错误。我也试过将 COUNT(transaction_id) WHERE due_date = '2016-05-16' 括在括号内，但没有用。

欢迎任何解决方案，谢谢。

Answer 1

我不明白在第二个查询中使用 WHERE 作为子查询无论如何只返回这些日期的意义

Answer 2

您将 where 放在 from 子句之前的子句顺序错误

SELECT 100 * (SELECT COUNT(transaction_id) 
        from t_transaction_main   
        WHERE due_date = '2016-05-16' and (suspend_status !='' OR
  close_date !='0-0000-00'))/COUNT(transaction_id) 
FROM t_transaction_main as test 
WHERE due_date = '2016-05-16' ;

Answer 3

WHERE 子句需要放在最后的 from t_transaction_main as test

之后

Answer 4

为什么要使用子查询？甚至两个聚合函数？

SELECT AVG(CASE WHEN suspend_status <> '' OR close_date <> '0-0000-00'
                THEN 100.0 ELSE 0
           END)
FROM t_transaction_main test 
WHERE due_date = '2016-05-16' ;

这比您原来的查询简单得多。

从两个 SQL Count() 结果计算百分比

Calculating percentage from two SQL Count() results

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percentage