有关SQL ORACLE中UPDATE的查询

Question

这是我的TABLE DESC：

Customer (Custid, Custname, Addr, phno,panno) 
Loan (Loanid, Amount, Interest, Custid)
Account (Accid, Accbal, Custid) 

现在我需要为指定的条件

更新表“loan”

QUERY IS：

Update the interest with 1% when Accbal >50% of Loan Amount 

我几乎不需要单线查询（SQL PLUS）。是否可以对此更新进行单行查询，还是应该创建更新过程。单行查询是最受欢迎的。

Answer 1

这样做

update Loan 
Set Interest = Interest + (1 * Interest )/100 
where Custid IN (select Custid from Account where Accbal > 50);

修改

update Loan 
Set Interest = Interest + (1 * Interest )/100 
where Custid IN (
    select a.Custid 
     from Account left outer join Loan 
       on Account.Custid = Loan.Custid 
        where Account.Accbal > (Loan.amount)/ 2
);