SQLAlchemy中的别名并集

在sqlalchemy中，我试图联合表，然后使用

WHERE

和

ORDER\u BY

差不多

SELECT *
FROM (
  SELECT [TABLE_ONE].[SOME_ID] AS [SOME_ID]
  FROM [TABLE_ONE] 
  UNION 
  SELECT [TABLE_TWO].[SOME_ID] AS [SOME_ID]
  FROM [TABLE_TWO]
) AS anon_1
WHERE ...

炼金术：

select_q = select([TABLE_ONE.c.SOME_ID], TABLE_ONE)
select_w = select([TABLE_TWO.c.SOME_ID], TABLE_TWO)
union_qw = union(select_q,select_w) 
union_qw_aliased = aliased(union_qw)
s = select('*',union_qw_aliased)

但是SQLAlchemy生成SQL代码：

SELECT anon_1.[SOME_ID]
FROM (SELECT [TABLE_ONE].[SOME_ID] AS [SOME_ID]
FROM [TABLE_ONE] UNION SELECT [TABLE_TWO].[SOME_ID] AS [SOME_ID]
FROM [TABLE_TWO]) AS anon_1
WHERE SELECT [TABLE_ONE].[SOME_ID]
FROM [TABLE_ONE] UNION SELECT [TABLE_TWO].[SOME_ID]
FROM [TABLE_TWO]

---

非常感谢您的帮助

您错误地使用了第二个参数“select（）”，这实际上就是“whereclause”（尽管我们现在鼓励使用

where（）

方法）。FROM子句通常在您选择的列中是隐式的。对于您的“select*”，我们可以使用

select\u FROM（）

设置显式的：

输出：

SELECT * 
FROM (SELECT t1.id AS id 
FROM t1 UNION SELECT t2.id AS id 
FROM t2) AS anon_1

SELECT * 
FROM (SELECT t1.id AS id 
FROM t1 UNION SELECT t2.id AS id 
FROM t2) AS anon_1 
WHERE anon_1.id = :id_1

要在何处执行更多操作，请使用

WHERE（）

添加该操作，并针对union_qw_别名执行该操作：

print s.where(union_qw_aliased.c.id == 5)

输出：

SELECT * 
FROM (SELECT t1.id AS id 
FROM t1 UNION SELECT t2.id AS id 
FROM t2) AS anon_1

SELECT * 
FROM (SELECT t1.id AS id 
FROM t1 UNION SELECT t2.id AS id 
FROM t2) AS anon_1 
WHERE anon_1.id = :id_1