Question

试图找出哪家银行拥有最多的钱..

SELECT *
FROM bank B
WHERE BSB IN (SELECT max(balance)
              FROM   registered R, Account A
              WHERE  R.BSB = B.BSB
              AND    A.accountNumber = R.accountNumber);

Answer 1

要说明问题可能有点困难，因为你没有提供发生了什么的声明，但我同意@AlexPoole将MAX(BALANCE)与BSB值进行比较（分支＃？）可能不是你想做的。也许以下内容证明是有用的：

SELECT *
  FROM bank B
  WHERE BSB = (SELECT BSB
                 FROM (SELECT R.BSB, SUM(balance)
                         FROM registered R
                         INNER JOIN Account A
                           ON R.BSB = B.BSB AND
                              R.accountNumber = A.accountNumber
                         ORDER BY SUM(BALANCE) DESC)
                 WHERE ROWNUM = 1)

使用CTE（公用表表达式）的稍微清洁的版本可能是：

WITH BRANCH_BALANCES AS (SELECT R.BSB, SUM(balance) AS BRANCH_BALANCE
                           FROM BANK B
                           INNER JOIN registered R
                             ON R.BSB = B.BSB
                           INNER JOIN Account A
                             ON R.accountNumber = A.accountNumber)
SELECT *
  FROM (SELECT BSB, BRANCH_BALANCE
          FROM BRANCH_BALANCES
          ORDER BY BRANCH_BALANCE DESC)
  WHERE ROWNUM = 1

祝你好运。

Answer 2

根据bank表中的字段数量，等到最后一个可能的步骤加入它并拉出一条记录（我假设有PK或至少和Bank.BSB上的索引。）

with balances as (
  select
    r.BSB, sum (a.balance) as balance_total
  from
    registered r,
    account a
  where
    r.accountNumber = a.accountNumber
  group by r.BSB
),
ranked_balances as (
  select
    BSB, balance_total,
    row_number() over (order by balance_total desc) as rn
  from balances
)
select
  b.*
from
  bank b,
  ranked_balances ba
where
  b.BSB = ba.BSB and
  ba.rn = 1

甲骨文 - 哪家银行根据客户账户持有大部分资金

2 个答案: