2

我对以下 sql 代码有疑问：我想打印出两年（2019 年和 2020 年）的计数。现在我只打印出 2020 年。你有什么想法或者可以帮助我处理这个 sql 吗？

     SELECT COUNT(u.id) AS total,  m.displayMonth
         FROM (
               SELECT 'Jan' as displayMonth, '01' AS MONTH
               UNION SELECT 'Feb' as displayMonth, '02' AS MONTH
               UNION SELECT 'Mar' as displayMonth,'03' AS MONTH
               UNION SELECT 'Apr' as displayMonth,'04' AS MONTH
               UNION SELECT 'May' as displayMonth,'05' AS MONTH
               UNION SELECT 'Jun' as displayMonth,'06' AS MONTH
               UNION SELECT 'Jul' as displayMonth,'07' AS MONTH
               UNION SELECT 'Aug' as displayMonth,'08' AS MONTH
               UNION SELECT 'Sep' as displayMonth,'09' AS MONTH
               UNION SELECT 'Okt' as displayMonth,'10' AS MONTH
               UNION SELECT 'Nov' as displayMonth,'11' AS MONTH
               UNION SELECT 'Dec' as displayMonth,'12' AS MONTH
              ) AS m
    LEFT JOIN wpiy_veosoft_crm_customer u 
    ON MONTH(STR_TO_DATE(CONCAT(m.month, ' 2020'),'%m %Y')) = MONTH(u.date)
       AND YEAR(u.date) = '2020'
    GROUP BY m.month

下面的 SQL 代码打印出来：

total   DisplayMonth
7           Jan
0           Feb
0           Mar
0           Apr
0           May
0           Jun
0           Jul
0           Aug
0           Sep
0           Okt
0           Nov
0           Dec

我想为 2020 年和 2019 年打印。所以下面的打印看起来像这样：

2019   2020    DisplayMonth
 5      7           Jan
 2      0           Feb
 1      0           Mar
 0      0           Apr
 0      0           May
 0      0           Jun
 0      0           Jul
 2      0           Aug
 1      0           Sep
 0      0           Okt
 4      0           Nov
 1      0           Dec
4

2 回答 2

2

您可以使用条件聚合：

 SELECT m.displayMonth,
        SUM(CASE WHEN YEAR(u.date) = 2019 THEN 1 ELSE 0 END ) as total_2019,
        SUM(CASE WHEN YEAR(u.date) = 2020 THEN 1 ELSE 0 END ) as total_2020
 FROM (SELECT 'Jan' as displayMonth, '01' AS MONTH UNION ALL
       SELECT 'Feb' as displayMonth, '02' AS MONTH UNION ALL
       SELECT 'Mar' as displayMonth, '03' AS MONTH UNION ALL
       SELECT 'Apr' as displayMonth, '04' AS MONTH UNION ALL
       SELECT 'May' as displayMonth, '05' AS MONTH UNION ALL
       SELECT 'Jun' as displayMonth, '06' AS MONTH UNION ALL
       SELECT 'Jul' as displayMonth, '07' AS MONTH UNION ALL
       SELECT 'Aug' as displayMonth, '08' AS MONTH UNION ALL
       SELECT 'Sep' as displayMonth, '09' AS MONTH UNION ALL
       SELECT 'Okt' as displayMonth, '10' AS MONTH UNION ALL
       SELECT 'Nov' as displayMonth, '11' AS MONTH UNION ALL
       SELECT 'Dec' as displayMonth, '12' AS MONTH
      ) m LEFT JOIN
      wpiy_veosoft_crm_customer u 
      ON MONTH(u.date) = m.month AND  -- implicit conversion here
         YEAR(u.date) IN (2019, 2020)
GROUP BY m.month, m.displayMonth
ORDER BY m.month;

注意查询的更改：

  • 使用UNION ALL而不是UNION. 没有理由承担删除重复项的开销。
  • 日期比较仅使用日期部分。
于 2020-01-02T14:44:43.503 回答
0

请尝试下面的代码将年份放在聚合函数中并根据条件进行更改

SELECT COUNT(u.id) AS total,  m.displayMonth,year(u.date)
         FROM (
               SELECT 'Jan' as displayMonth, '01' AS MONTH
               UNION SELECT 'Feb' as displayMonth, '02' AS MONTH
               UNION SELECT 'Mar' as displayMonth,'03' AS MONTH
               UNION SELECT 'Apr' as displayMonth,'04' AS MONTH
               UNION SELECT 'May' as displayMonth,'05' AS MONTH
               UNION SELECT 'Jun' as displayMonth,'06' AS MONTH
               UNION SELECT 'Jul' as displayMonth,'07' AS MONTH
               UNION SELECT 'Aug' as displayMonth,'08' AS MONTH
               UNION SELECT 'Sep' as displayMonth,'09' AS MONTH
               UNION SELECT 'Okt' as displayMonth,'10' AS MONTH
               UNION SELECT 'Nov' as displayMonth,'11' AS MONTH
               UNION SELECT 'Dec' as displayMonth,'12' AS MONTH
              ) AS m
    LEFT JOIN wpiy_veosoft_crm_customer u 
    ON  MONTH(u.date) = m.month

       AND YEAR(u.date) in(‘2019’, '2020')
    GROUP BY m.month,year(u.date)
于 2020-01-02T14:51:36.110 回答