将 SQL 转换为 SQLAlchemy 一答案

【问题标题】：Convert SQL to SQLAlchemy one将 SQL 转换为 SQLAlchemy 一
【发布时间】：2021-11-21 09:39:57
【问题描述】：

我有这个 SQL 代码，我想用 SQLAlchemy 执行它。但我无法使用 SQLAlchemy 编写正确的查询。

SELECT anon_1.applications_versions_id             AS versions_id,
       anon_1.applications_versions_application_id AS versions_application_id,
       anon_1.applications_versions_version        AS version,
       anon_1.applications_versions_status         AS status,
       anon_1.applications_id                      AS applications_id,
       anon_1.applications_developer_id            AS developer_id,
       anon_1.applications_name                    AS name,
       anon_1.applications_description             AS description
FROM (
         SELECT DISTINCT ON
             (applications_versions.application_id) applications_versions.id             AS applications_versions_id,
                                                    applications_versions.application_id AS applications_versions_application_id,
                                                    applications_versions.version        AS applications_versions_version,
                                                    applications_versions.path           AS applications_versions_path,
                                                    applications_versions.status         AS applications_versions_status,
                                                    applications_versions.release_notes  AS applications_versions_release_notes,
                                                    applications_versions.created        AS applications_versions_created,
                                                    applications_versions.updated        AS applications_versions_updated,
                                                    applications.id                      AS applications_id,
                                                    applications.developer_id            AS applications_developer_id,
                                                    applications.name                    AS applications_name,
                                                    applications.description             AS applications_description,
                                                    applications.created                 AS applications_created,
                                                    applications.updated                 AS applications_updated
         FROM applications
                  JOIN applications_versions ON applications.id = applications_versions.application_id
         ORDER BY applications_versions.application_id, applications_versions.created DESC) AS anon_1
WHERE anon_1.applications_versions_status = 'DECLINED'
ORDER BY anon_1.applications_versions_application_id, anon_1.applications_versions_created DESC;

有人可以帮我解决这个问题吗？

【问题讨论】：

标签： sql sqlalchemy

【解决方案1】：

这里有两种解决方案。

简单

您将查询包装在 from_statement 中并进一步使用它。

例子：

from sqlalchemy import text
apps = session.query(Application).from_statement(text(
"""
SELECT ...
FROM ...
ORDER BY ...
""")).all()

很难

您学习 SQLAlchemy 并自己重写。

这些链接将对您有所帮助：

SELECT, WHERE and ORDER BY operators in SQLAlchemy ORM
Common Table Expression（此函数根据您的查询创建子查询）

【讨论】：