Question

我有一些表格：

＆＃34;分支＆＃34; table（branch_name，branch_city，assets）
＆＃34;顾客＆＃34; table（customer_name，customer_street，customer_city）
＆＃34;帐户＆＃34; table（account_number，branch_name，balance）
＆＃34; loan＆＃34; table（loan_number，branch_name，amount）
＆＃34;存款人＆＃34;表（customer_name，account_number）
＆＃34;借款人＆＃34; table（customer_name，loan_number）

现在我想找到所有在Perryridge分行同时拥有账户和贷款的客户。

我写的SQL查询是

SELECT distinct customer_name 
FROM borrower, loan
WHERE borrower.loan_number = loan.loan_number 
      AND branch_name = 'Perryridge' 
      AND (branch_name, customer_name )     
          IN (SELECT branch_name, customer_name 
             FROM depositor, account
             WHERE depositor.account_number = account.account_number )

我想知道是否还有其他更简单的SQL查询可以完成相同的问题，例如使用TABLE UNION。

Answer 1

try this updated script




SELECT DISTINCT
  customer_name
FROM customer c
INNER JOIN depositor d
  ON d.customer_name=c.customer_name
inner join accounts a on d.account_number = a.account_number
 INNER JOIN borrower b
  ON b.customer_name = c.customer_name
INNER JOIN loan l
  ON l.loan_number = b.loan_number
WHERE l.branch_name = a.branch_name 
AND l.branch_name = 'Perryridge'

Answer 2

选择不同的客户名称来自借款人，贷款 WHERE借款人。贷款编号=贷款。贷款编号 AND branch_name ='Perryridge' AND（分支名称，客户名称）
IN（选择branch_name，customer_name 从存款人，帐户在哪里depositor.account_number = account.account_number）

查找在Perryridge分行同时拥有帐户和贷款的所有客户

2 个答案: