blocks|key|1626730|text|来自alembic+documentation+(重点是我的)：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1626731|1626732|+sqlalchemy.url+-通过SQLAlchemy连接到数据库的URL。该配置值仅在env.py文件调用它们时使用；在“通用”模板中，在run_migrations_offline()函数中对config.get_main_option("sqlalchemy.url")的调用和对engine_from_config(prefix=“sqlalchemy”)的调用。在run_migrations_online()函数中是引用此键的位置。如果SQLAlchemy+URL应来自其他来源，例如来自环境变量或全局注册表，或者如果迁移环境使用多个数据库URL，鼓励开发人员更改env.py文件以使用任何适当的方法来获取一个或多个数据库URL。|blockquote|style|BOLD|1626733|1626734|1626735|因此，在这种情况下，sqlalchemy+url格式可以由python本身循环生成。|1626736|entityMap|0|LINK|mutability|MUTABLE|url|https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file^0|2|L|0|0|0|68|12|7U|E|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@$A|W|B|X|1|Y]]|C|$]]|$1|D|3|-4|5|6|7|Z|8|@]|9|@]|C|$]]|$1|E|3|F|5|G|7|10|8|@$A|11|B|12|H|I]|$A|13|B|14|H|I]]|9|@]|C|$]]|$1|J|3|-4|5|6|7|15|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|16|8|@]|9|@]|C|$]]|$1|L|3|M|5|6|7|17|8|@]|9|@]|C|$]]|$1|N|3|-4|5|6|7|18|8|@]|9|@]|C|$]]]|O|$P|$5|Q|R|S|C|$T|U]]]]

From the <a href="https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file" rel="nofollow noreferrer">alembic documentation</a> (emphasis mine):

<blockquote>
 sqlalchemy.url - A URL to connect to the database via SQLAlchemy. This configuration value is only used if the env.py file calls upon them; in the “generic” template, the call to config.get_main_option("sqlalchemy.url") in the run_migrations_offline() function and the call to engine_from_config(prefix="sqlalchemy.") in the run_migrations_online() function are where this key is referenced. If the SQLAlchemy URL should come from some other source, such as from environment variables or a global registry, or if the migration environment makes use of multiple database URLs, the developer is encouraged to alter the env.py file to use whatever methods are appropriate in order to acquire the database URL or URLs.
</blockquote>

So for this case, the sqlalchemy url format can be circunvented and generated by python itself.

blocks|key|3279969|text|我已经通过在env.py导入config对象后立即修改该对象中的值来解决此问题：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3279970|#+this+is+the+Alembic+Config+object,+which+provides
#+access+to+the+values+within+the+.ini+file+in+use.
config+=+context.config

#+import+my+custom+configuration
from+my_app+import+MY_DB_URI
#+overwrite+the+desired+value
config.set_main_option("sqlalchemy.url",+MY_DB_URI)|code-block|syntax|javascript|3279971|现在config.get_main_option("sqlalchemy.url")返回您想要的MY_DB_URI。|3279972|entityMap^0|6|6|E|6|0|0|2|14|1C|9|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|N|$]]

I have gone around this issue by modifying the values in the <code>config</code> object just after <code>env.py</code> imports it:
<pre class="lang-py prettyprint-override"><code># this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

# import my custom configuration
from my_app import MY_DB_URI
# overwrite the desired value
config.set_main_option(&quot;sqlalchemy.url&quot;, MY_DB_URI)
</code></pre>
Now <code>config.get_main_option(&quot;sqlalchemy.url&quot;)</code> returns the <code>MY_DB_URI</code> you wanted.

blocks|key|1634877|text|正如其他人所指出的，一个键是相对的3个斜杠，绝对的4个斜杠。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1634878|但我需要的不仅仅是这些..。|1634879|在处理字符串时遇到问题，我不得不这样做：|1634880|db_dir+=+"../../database/db.sqlite"
print(f'os.path.abspath(db_dir):+{str(os.path.abspath(db_dir))}')
SQLALCHEMY_DATABASE_URI+=+"sqlite:///"+%2B+os.path.abspath(db_dir)++#+works
#+SQLALCHEMY_DATABASE_URI+=+"sqlite:///"+%2B+db_dir++#+fails|code-block|syntax|javascript|1634881|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

As others have pointed out, one key is 3 slashes for relative, 4 for absolute.
But it took for me than just that...
Had trouble with just a string, I had to do this:
<pre><code>db_dir = &quot;../../database/db.sqlite&quot;
print(f'os.path.abspath(db_dir): {str(os.path.abspath(db_dir))}')
SQLALCHEMY_DATABASE_URI = &quot;sqlite:///&quot; + os.path.abspath(db_dir) # works
# SQLALCHEMY_DATABASE_URI = &quot;sqlite:///&quot; + db_dir # fails
</code></pre>

A relative sqlalchemy path to a sqlite database can be written as:

<pre class="lang-none prettyprint-override"><code>sqlite:///folder/db_file.db
</code></pre>

And an absolute one as:

<pre class="lang-none prettyprint-override"><code>sqlite:////home/user/folder/db_file.db
</code></pre>

Is it possible to write a path relative to home? Like this:

<pre class="lang-none prettyprint-override"><code>sqlite:///~/folder/db_file.db
</code></pre>

Or even better, can the path contain environment variables?

<pre class="lang-none prettyprint-override"><code>sqlite:////${MY_FOLDER}/db_file.db
</code></pre>

This is the context of an alembic.ini file. So if the previous objectives are not possible directly, may I be able to cheat using variable substitution?

<pre><code>[alembic]
script_location = db_versions
sqlalchemy.url = sqlite:///%(MY_FOLDER)s.db
...
</code></pre>

Sqlalchemy sqlite url relative to home or environment variable

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

指向sqlite数据库的相对sqlalchemy路径可以写成：sqlite:///folder/db_file.db和一个绝对的，如：sqlite:////home/user/folder/db_file.db有没有可能写一个相对于home的路径？如下所示：sqlite:///~/folder/db_file.db或者...

问相对于home或环境变量的Sqlalchemy sqlite url
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问相对于home或环境变量的Sqlalchemy sqlite urlEN