Question

我正在尝试从称为“行为”的表中获取摘要统计信息，该表存储了有关捐赠的数据。在此过程中，我想获得一个表格，其中包含与所有捐赠，非自动捐赠（DO）和自动捐赠（PA）有关的统计信息。为此，我使用了两个左连接（在同一表上，但具有不同的group by子句）。

我的查询返回以下错误：

错误代码：1054。未知列'a.yr。在“在子句中”

能否请您帮我找到解决这个问题的方法，或者提出实现我目标的另一种方法？非常感谢你！

SELECT 
    YEAR(a.act_date)                    AS yr, 
    SUM(a.amount)                       AS sum_all, 
    COUNT(a.amount)                     AS nb_all, 
    AVG(a.amount)                       AS avg_all, 
    COUNT(DISTINCT(a.contact_id))       AS unique_all,
    sum_do,
    nb_do,
    avg_do,
    unique_do,
    sum_pa,
    nb_pa,
    avg_pa,
    unique_pa
FROM
    acts a
LEFT JOIN
    (SELECT 
        YEAR(act_date)                  AS yr_do, 
        SUM(amount)                     AS sum_do, 
        COUNT(amount)                   AS nb_do, 
        AVG(amount)                     AS avg_do, 
        COUNT(DISTINCT(contact_id))     AS unique_do
    FROM
        acts  
    WHERE
        YEAR(act_date) >= 1991 AND
        act_type_id LIKE 'DO'
    GROUP BY
        1) 
    AS donation
ON a.yr = donation.yr_do
LEFT JOIN
    (SELECT 
        YEAR(act_date)                  AS yr_pa, 
        SUM(amount)                     AS sum_pa, 
        COUNT(amount)                   AS nb_pa, 
        AVG(amount)                     AS avg_pa, 
        COUNT(DISTINCT(contact_id))     AS unique_pa
    FROM
        acts 
    WHERE
        YEAR(act_date) >= 1991 AND
        act_type_id LIKE 'PA'
    GROUP BY
        1) 
    AS pa
ON a.yr = pa.yr_pa
WHERE
    YEAR(act_date) >= 1991
GROUP BY
    1;

Answer 1

您不能在同一查询中使用select中定义的别名。对于演示：

select YEAR(a.dt) myDt, myDt from T

也是无效的。更改

ON a.yr = donation.yr_do

到

ON YEAR(a.act_date) = donation.yr_do

多个带有子查询的左联接返回“未知列”错误

1 个答案: