SQLAlchemy - 获取表列表

SQLAlchemy - Getting a list of tables(SQLAlchemy - 获取表列表)

问题描述

我在文档中找不到任何关于此的信息，但是如何获取在 SQLAlchemy 中创建的表的列表?

我使用类方法来创建表.

所有的表都收集在 SQLAlchemy MetaData 对象的 tables 属性中.要获取这些表的名称列表:

对于 Postgres，如果您有多个模式，则需要遍历引擎中的所有模式:

from sqlalchemy import inspect检查员 = 检查(引擎)schemas = inspector.get_schema_names()对于模式中的模式:打印(架构:%s"%架构)对于 inspector.get_table_names(schema=schema) 中的 table_name:对于 inspector.get_columns(table_name, schema=schema) 中的列:打印(列:%s"%列)

I couldn't find any information about this in the documentation, but how can I get a list of tables created in SQLAlchemy?

I used the class method to create the tables.

All of the tables are collected in the tables attribute of the SQLAlchemy MetaData object. To get a list of the names of those tables:

>>> metadata.tables.keys()
['posts', 'comments', 'users']

If you're using the declarative extension, then you probably aren't managing the metadata yourself. Fortunately, the metadata is still present on the baseclass,

>>> Base = sqlalchemy.ext.declarative.declarative_base()
>>> Base.metadata
MetaData(None)

If you are trying to figure out what tables are present in your database, even among the ones you haven't even told SQLAlchemy about yet, then you can use table reflection. SQLAlchemy will then inspect the database and update the metadata with all of the missing tables.

>>> metadata.reflect(engine)

For Postgres, if you have multiple schemas, you'll need to loop thru all the schemas in the engine:

from sqlalchemy import inspect
inspector = inspect(engine)
schemas = inspector.get_schema_names()

for schema in schemas:
    print("schema: %s" % schema)
    for table_name in inspector.get_table_names(schema=schema):
        for column in inspector.get_columns(table_name, schema=schema):
            print("Column: %s" % column)

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