Question

我写了一个查询，显示了每个州每年取消订单的原因和所选原因的数量：

SELECT   DISTINCT LEFT(k.wijk,2) AS state,
         YEAR(a.eind_dt) AS year, 
         opzegreden AS reason, 
         count(*) AS amount
FROM     klant AS k 
JOIN     abon AS a 
ON       k.klant_id = a.lezer
WHERE    opzegreden IS NOT NULL
GROUP BY LEFT(k.wijk,2), year(a.eind_dt), opzegreden
ORDER BY state, year, reason;

这给出了这个结果atm： Current result

现在我唯一无法实现的目的是显示每年每州最多的原因。我目前的结果是14号的原因。

有人可以帮帮我吗？

Answer 1

您可以将top with ties与窗口函数row_number配对，以获得每年每州最大金额的行。

select top 1 with ties LEFT(k.wijk, 2) as state,
    YEAR(a.eind_dt) as year,
    opzegreden as reason,
    count(*) as amount
from klant as k
join abon as a on k.klant_id = a.lezer
where opzegreden is not null
group by LEFT(k.wijk, 2),
    year(a.eind_dt),
    opzegreden
order by row_number() over (
        partition by state, year order by amount desc
        );

Answer 2

你可以试试这个： -

    SELECT
      state,
      year,
      reason,
      max(amount)
    FROM
    (
    SELECT DISTINCT LEFT(k.wijk,2) AS state,
    YEAR(a.eind_dt) AS year, 
    opzegreden AS reason, count(*) AS amount
    FROM klant AS k 
    JOIN abon AS a 
    ON k.klant_id = a.lezer
    WHERE opzegreden IS NOT NULL
    GROUP BY LEFT(k.wijk,2), year(a.eind_dt), opzegreden
    ORDER BY state, year, reason
    ) d
GROUP BY
  state,
  year,
  reason;

你如何选择最高的计数（）？

2 个答案: