oracle10g - 如何使用 "as"为 oracle 10 中的连接表设置别名

Question

我写了这个，这是错误的语法，帮我修复它，我希望 'T' 成为两个内部连接结果的别名。

select T.id 
from table1 
  inner join table2 on table1.x = table2.y  
  inner join table3 on table3.z = table1.w as T;

Answer 1

您不能直接命名连接的结果。一种选择是使用子查询:

select T.id
from (
  select *
  from table1
  inner join table2 on table1.x = table2.y
  inner join table3 on table3.z = table1.w
) T

另一种选择是子查询分解:

with T as (
  select *
  from table1
  inner join table2 on table1.x = table2.y
  inner join table3 on table3.z = table1.w
)
select T.id
from T