不知道效率怎么样……set timing on
Select a.class,a.name,
Max(decode(a.subject,'语文',a.scores)) 期末语文,
Max(decode(a.subject,'数学',a.scores)) 期末数学,
Max(decode(a.subject,'政治',a.scores)) 期末政治,
Max(decode(b.subject,'语文',b.scores)) 期中语文,
Max(decode(b.subject,'数学',b.scores)) 期中数学,
Max(decode(b.subject,'政治',b.scores)) 期中政治
From a,b
Where a.name=b.Name And a.Name='王1'
Group By a.class,a.name
Select a.class,a.name,
Max(decode(a.subject,'语文',a.scores)) 期末语文,
Max(decode(a.subject,'数学',a.scores)) 期末数学,
Max(decode(a.subject,'政治',a.scores)) 期末政治,
Max(decode(b.subject,'语文',b.scores)) 期中语文,
Max(decode(b.subject,'数学',b.scores)) 期中数学,
Max(decode(b.subject,'政治',b.scores)) 期中政治
From a,b
Where a.name=b.Name And a.Name='王1'
Group By a.class,a.name
哪个不是group by表达式?
把你执行的代码贴出来看看