Sql抓住最近的记录

Question

我目前正在使用DBISAM sql编译器。它与ms sql编译器非常相同，唯一的区别是我不能有任何嵌套的连接语句。

以下查询是一个嵌套查询，用于获取最新的贷款记录和费率。我想知道是否有另一种方法可以在没有嵌套的select语句的情况下编写它。

select * from 
(select Loan_Id, Max(effectiveDate) as EffectiveDate from InterestTerms 
group by Loan_Id) as Y
join InterestTerms as X on Y.Loan_Id = X.Loan_Id and Y.EffectiveDate = X.EffectiveDate
order by Y.Loan_Id

Answer 1

您可以尝试以下方法：

select 
    X.*
FROM
    InterestTerms AS X
WHERE
    X.effectiveDate IN (
     select 
          Max(Y.effectiveDate) as MaxED  
     from 
          InterestTerms as Y
     WHERE
          Y.Loan_Id = X.Loan_Id
    ) 
order by 
    X.Loan_Id

<强>（修订版）