Question

此查询生成从1到4的数字。

with recursive z(q) as (
  select 1
  union all
  select q + 1 from z where q < 4
  )
select * from z;

但是，如果我将其修改为此，

with x as (
  select 1 y
  ),
recursive z(q) as (
  select y from x
  union all
  select q + 1 from z where q < 4
  )
select * from z;

它给出了

错误：“z”或附近的语法错误

我在这里做错了什么？

Answer 1

我认为这是因为RECURSIVE is modifier of WITH statement，而不是公用表格式z的属性，所以你可以像这样使用它：

with recursive
x as (
  select 1 y
),
z(q) as (
  select y from x
  union all
  select q + 1 from z where q < 4
)
select * from z;