科(branch_name,branch_city,资产)
顾客(CUSTOMER_NAME,customer_street,customer_city)
贷款(loan_number,branch_name之间的差异,量)
借款人(CUSTOMER_NAME,loan_number)
帐户(ACCOUNT_NUMBER,branch_name,平衡)
存款(CUSTOMER_NAME,ACCOUNT_NUMBER)“=” 和 “IN”/ “NOT IN” 和 “MINUS”
如何是 “=” 和 “IN” 和 “NOT IN” 和“ MINUS“在
select c.customer_name
from Customer c, Borrower b, Loan l
where c.customer_city = 'Fairfax AND c.customer_name = b.customer_name
AND b.loan_number = l.loan_number
minus
select d.customer_name
from Depositer d, Account a
where d.account_number = a.account_number
和
select c.customer_name
from Customer c
where c.customer_city = 'Fairfax' AND c.customer_name in
(select b.customer_name
from Borrower b
where b.loan_number in
(select l.loan_number
from Loan l
where b.customer_name not in
(select d.customer_name
from Account a, Depositor d
where a.account_number = d.account_number)))
彼此不同?他们应该完成相同的事情
通常... =运算符用于单个值检查,其中IN用于执行多值检查。 – Teja 2012-03-28 19:45:53
你在第一个查询中缺少'b'的声明,可能想补充一点,所以人们知道你从哪里得到它 – jzworkman 2012-03-28 19:46:32
令人惊讶的是......或者不......这些都在[参考手册](http ://dev.mysql.com/doc/refman/5.5/en/select.html) – 2012-03-28 19:56:07