为什么sqlalchemy的默认列值不起作用

Ayl*_*ake 18 python postgresql

我正在使用Postgresql 9.1和SQLAlchemy 0.9.

问题是,' default = 10 '不起作用.

我的代码:

conn_str = 'postgresql://test:pass@localhost/test'
engine = create_engine(conn_str)
metadata = MetaData(bind=engine)

cols=[]
cols += [Column('Name', VARCHAR(20), primary_key=True, nullable=False)]
cols += [Column('age', INT, default=10, nullable=False )]
Table('t1', metadata, *cols)
metadata.create_all(engine)
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PSQL:

test=> \dS t1
            Table "public.t1"
Column |         Type          | Modifiers
--------+-----------------------+-----------
Name   | character varying(20) | not null
age    | integer               | not null
Indexes:
    "t1_pkey" PRIMARY KEY, btree ("Name")
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我直接尝试使用SQL语句,它应该如下所示:

test=> \dS t2
              Table "public.t2"
 Column |         Type          | Modifiers
--------+-----------------------+------------
 Name   | character varying(10) | not null
 age    | integer               | default 10
Indexes:
    "t2_pkey" PRIMARY KEY, btree ("Name")
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我究竟做错了什么?