Question

在SQLITE数据库中，如果我需要表元数据，我可以运行以下命令

C:\sqlite>sqlite3.exe sqlite2.db
SQLite version 3.7.15 2012-12-12 13:36:53
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> PRAGMA table_info(forum_forum);
0|id|integer|1||1
1|category_id|integer|0||0
2|name|varchar(100)|1||0
3|description|varchar(200)|1||0
4|locked|bool|1||0

我想在sqlalchemy中做类似的事情。有人能告诉我怎么做吗？

解决方案

from sqlalchemy import *
from sqlalchemy.orm import sessionmaker

db_target = create_engine('sqlite:///C:\\Users\\asit\\workspace\\forum1\\src\\sqlite.db')
session = sessionmaker(db_target, autocommit = True)()

rs = session.execute("PRAGMA table_info(forum_forum)")
for row in rs:
    print '%s %s %s %s %s' % (row['cid'], row['name'], row['type'], row['notnull'], row['pk'])

输出： -

0 id integer 1 1
1 category_id integer 0 0
2 name varchar(100) 1 0
3 description varchar(200) 1 0
4 locked bool 1 0

Answer 1

您可以使用session.execute()运行任意SQL语句，包括该pragma语句。

PRAGMA table_info(forum_forum)语句返回一系列行：

>>> res = session.execute("PRAGMA table_info(forum_forum)")
>>> res.keys()
[u'cid', u'name', u'type', u'notnull', u'dflt_value', u'pk']
>>> for row in res:
...     print row
... 
(0, u'id', u'integer', 0, None, 1)
(1, u'category_id', u'integer', 0, None, 0)
(2, u'name', u'varchar(100)', 1, None, 0)
(3, u'description', u'varchar(200)', 1, None, 0)
(4, u'locked', u'bool', 1, None, 0)

Answer 2

你可以通过以下方式获得很多细节

from sqlalchemy import *

db_target = create_engine('sqlite:///C:\\Users\\asit\\workspace\\forum1\\src\\sqlite.db')
target_metadata = MetaData(db_target)
src_master_table = Table('forum_forum', src_metadata, autoload=True )
print src_master_table.columns._data

sqlite3中的列详细信息

解决方案

2 个答案: