[英]Python Flask SQLalchemy query filter by boolean values ignore False
[英]SQLAlchemy query renders .filter() as "WHERE false"
我的问题归结为以下使用 Python3.8 和 SQLAlchemy1.3 运行的代码:
subquery = (
session.query(
Article.id,
SubscriberArticle.subscriber_id,
SubscriberArticle.data,
SubscriberArticle.is_activated,
)
.join(SubscriberArticle)
.filter(and_(
SubscriberArticle.subscriber_id == 1234,
Article.is_activated is True
))
.subquery()
)
query = (
session.query(
Article.id,
Article.name,
subquery.c.subscriber_id,
subquery.c.data,
subquery.c.is_activated,
)
.join(subquery, subquery.c.id == Article.id)
)
where
子句不是我所期望的,这是我所期望的 SQL 请求:
SELECT
article.id,
article.name,
tmp.subscriber_id,
tmp.data,
tmp.is_activated
FROM
script_pixel
LEFT JOIN
(
SELECT
article.id,
subscriber_article.subscriber_id,
subscriber_article.data,
subscriber_article.is_activated
FROM
script_pixel
LEFT JOIN
subscriber_script_pixel
ON
subscriber_article.script_pixel_id = article.id
WHERE
subscriber_article.subscriber_id = 1234
AND
article.is_activated = true
) as tmp
ON
tmp.id = article.id;
但是当我做一个print("query", str(query))
结果是完全不同的:
SELECT
script_pixel.id AS script_pixel_id,
script_pixel.name AS script_pixel_name,
anon_1.subscriber_id AS anon_1_subscriber_id,
anon_1.data AS anon_1_data,
anon_1.is_activated AS anon_1_is_activated
FROM
script_pixel
JOIN (
SELECT
script_pixel.id AS id,
subscriber_script_pixel.subscriber_id AS subscriber_id,
subscriber_script_pixel.data AS data,
subscriber_script_pixel.is_activated AS is_activated
FROM
script_pixel
JOIN subscriber_script_pixel ON script_pixel.id = subscriber_script_pixel.script_pixel_id
WHERE
false
) AS anon_1 ON anon_1.id = script_pixel.id
正如您在我的子查询中看到的那样,我没有where
子句,而是有一个where false
无处不在。
您的问题是Article.is_activated is True
,这不能由 SQLAlchemy 编译,导致WHERE false
或WHERE 1=0
。
.filter(and_(
SubscriberArticle.subscriber_id == 1234,
Article.is_activated is True
))
您可以使用Article.is_activated == True
代替。 此外,您实际上并不需要and_
函数,因为Query.filter()
接受任意数量的条件,并将使用and_
为您加入它们。
.filter(
SubscriberArticle.subscriber_id == 1234,
Article.is_activated == True,
)
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