如何将 SQL SERVER 查询转换为 Oracle SQL？

Question

我正在尝试将下面的查询从 SQL Server 转换为 Oracle SQL。我不确定 关于预言机的 IFF 条件。

SELECT IIF(Grade<8, NULL,Name) As Name ,Grade,Marks 
FROM Grade,Students 
WHERE Marks>=Min_Mark and Marks<=Max_Mark 
ORDER BY Grade DESC, Name ASC;

Answer 1

你可以像下面这样尝试

SELECT case when Grade<8 then  NULL else Name end As Name ,Grade,Marks 
FROM Grade,Students 
WHERE Marks>=Min_Mark and Marks<=Max_Mark 
ORDER BY Grade DESC, Name ASC;

但我更喜欢像下面这样的显式加入

SELECT case when Grade<8 then  NULL else Name end As Name ,Grade,Marks 
    FROM Grade join Students 
    on  Grade.Marks>=Students.Min_Mark and
       Grade.Marks<=Students.Max_Mark 
    ORDER BY Grade DESC, Name ASC;