来源：http://blog.itpub.net/26515977/viewspace-1208256/　　

本文中 SQLAlchemy部分可参考http://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/0014320114981139589ac5f02944601ae22834e9c521415000

弓在箭要射出之前，低声对箭说道，“你的自由是我的”。Schema如箭，弓似Python，选择Python，是Schema最大的自由。而自由应是一个能使自己变得更好的机会。

㈠ MySQLdb部分

mysql> use sakila;
mysql> desc actor;
+-------------+----------------------+------+-----+-------------------+-----------------------------+
| Field       | Type                 | Null | Key | Default           | Extra                       |
+-------------+----------------------+------+-----+-------------------+-----------------------------+
| actor_id    | smallint(5) unsigned | NO   | PRI | NULL              | auto_increment              |
| first_name  | varchar(45)          | NO   |     | NULL              |                             |
| last_name   | varchar(45)          | NO   | MUL | NULL              |                             |
| last_update | timestamp            | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+-------------+----------------------+------+-----+-------------------+-----------------------------+
4 rows in set (0.00 sec)

[root@DataHacker ~]# cat dbapi.py
#!/usr/bin/env ipython
#coding = utf-8
#Author: linwaterbin@gmail.com
#Time: 2014-1-29import MySQLdb as dbapiUSER = \'root\'
PASSWD = \'oracle\'
HOST = \'127.0.0.1\'
DB = \'sakila\'conn = dbapi.connect(user=USER,passwd=PASSWD,host=HOST,db=DB)

[root@DataHacker ~]# cat QueryColumnMetaData.py
#!/usr/bin/env ipythonfrom dbapi import *cur = conn.cursor()
statement = """select * from actor limit 1"""
cur.execute(statement)print "output column metadata....."
print
for record in cur.description:print recordcur.close()
conn.close()

[root@DataHacker ~]# chmod +x QueryColumnMetaData.py
[root@DataHacker ~]# ./QueryColumnMetaData.py
output column metadata.....(\'actor_id\', 2, 1, 5, 5, 0, 0)
(\'first_name\', 253, 8, 45, 45, 0, 0)
(\'last_name\', 253, 7, 45, 45, 0, 0)
(\'last_update\', 7, 19, 19, 19, 0, 0)

In [1]: from dbapi import *In [2]: cur = conn.cursor()In [3]: v_sql = "select actor_id,last_name from actor limit 2"In [4]: cur.execute(v_sql)
Out[4]: 2LIn [5]: results = cur.fetchone()In [6]: print results[0]
58In [7]: print results[1]
AKROYD

In [2]: import MySQLdb.cursorsIn [3]: import MySQLdbIn [4]: conn = MySQLdb.connect(user=\'root\',passwd=\'oracle\',host=\'127.0.0.1\',db=\'sakila\',cursorclass=MySQLdb.cursors.DictCursor)In [5]: cur = conn.cursor()In [6]: v_sql = "select actor_id,last_name from actor limit 2"In [7]: cur.execute(v_sql)
Out[7]: 2LIn [8]: results = cur.fetchone()In [9]: print results[\'actor_id\']
58In [10]: print results[\'last_name\']
AKROYD

㈡ SQLAlchemy--SQL炼金术师

SQLAlchemy连接模块：
[root@DataHacker Desktop]# cat sa.py
import sqlalchemy as sa
engine = sa.create_engine(\'mysql://root:oracle@127.0.0.1/testdb\',pool_recycle=3600)
metadata = sa.MetaData()

In [3]: t = Table(\'t\',metadata,...:                Column(\'id\',Integer),...:                Column(\'name\',VARCHAR(20)),...:                mysql_engine=\'InnoDB\',...:                mysql_charset=\'utf8\'...:              )In [4]: t.create(bind=engine)

有2种方式，其一：
In [5]: t.drop(bind=engine,checkfirst=True)
另一种是：
In [5]: metadata.drop_all(bind=engine,checkfirst=True)，其中可以借助tables属性指定要删除的对象

3 .1 primary key
下面2种方式都可以，一个是列级，一个是表级
In [7]: t_pk_col = Table(\'t_pk_col\',metadata,Column(\'id\',Integer,primary_key=True),Column(\'name\',VARCHAR(20)))In [8]: t_pk_col.create(bind=engine)In [9]: t_pk_tb = Table(\'t_pk_01\',metadata,Column(\'id\',Integer),Column(\'name\',VARCHAR(20)),PrimaryKeyConstraint(\'id\',\'name\',name=\'prikey\'))In [10]: t_pk_tb.create(bind=engine)3.2 Foreign Key
In [13]: t_fk = Table(\'t_fk\',metadata,Column(\'id\',Integer,ForeignKey(\'t_pk.id\')))In [14]: t_fk.create(bind=engine)In [15]: t_fk_tb = Table(\'t_fk_tb\',metadata,Column(\'col1\',Integer),Column(\'col2\',VARCHAR(10)),ForeignKeyConstraint([\'col1\',\'col2\'],[\'t_pk.id\',\'t_pk.name\']))In [16]: t_fk_tb.create(bind=engine)3.3 unique
In [17]: t_uni = Table(\'t_uni\',metadata,Column(\'id\',Integer,unique=True))In [18]: t_uni.create(bind=engine)In [19]: t_uni_tb = Table(\'t_uni_tb\',metadata,Column(\'col1\',Integer),Column(\'col2\',VARCHAR(10)),UniqueConstraint(\'col1\',\'col2\'))In [20]: t_uni_tb.create(bind=engine)3.4 check虽然能成功，但MySQL目前尚未支持check约束。这里就不举例了。
3.5 not null
In [21]: t_null = Table(\'t_null\',metadata,Column(\'id\',Integer,nullable=False))In [22]: t_null.create(bind=engine)

4.1 例子：insert
In [23]: t_def_inser = Table(\'t_def_inser\',metadata,Column(\'id\',Integer),Column(\'name\',VARCHAR(10),server_default=\'cc\'))In [24]: t_def_inser.create(bind=engine)3.2 例子：update
In [25]: t_def_upda = Table(\'t_def_upda\',metadata,Column(\'id\',Integer),Column(\'name\',VARCHAR(10),server_onupdate=\'DataHacker\'))In [26]: t_def_upda.create(bind=engine)
3.3 例子：Passive
In [27]: t_def_pass = Table(\'t_def_pass\',metadata,Column(\'id\',Integer),Column(\'name\',VARCHAR(10),DefaultClause(\'cc\')))In [28]: t_def_pass.create(bind=engine)

版本：
[root@DataHacker ~]# ./sesc.py --version
1.0查看帮助：
[root@DataHacker ~]# ./sesc.py -h
Usage: sesc.py [options] <arg1> <arg2> [<arg3>...]Options:--version             show program\'s version number and exit-h, --help            show this help message and exit-q TERM               assign where predicate-c COL, --column=COL  assign query column-t TABLE              assign query table-f, --format          -f must match up -o-o OUTFILE            assign output file我们要的效果：
[root@DataHacker ~]# ./sesc.py -t actor -c last_name -q s% -f -o output.txt
[root@DataHacker ~]# cat output.txt
************ 1 row *******************actor_id: 180
first_name: JEFF
last_name: SILVERSTONE
last_update: 2006-02-15 04:34:33************ 2 row *******************actor_id: 195
first_name: JAYNE
last_name: SILVERSTONE
last_update: 2006-02-15 04:34:33
......<此处省略大部分输出>......

#!/usr/bin/env python
import optparse
from dbapi import *#构造OptionParser实例，配置期望的选项
parser = optparse.OptionParser(usage="%prog [options] <arg1> <arg2> [<arg3>...]",version=\'1.0\',)
#定义命令行选项，用add_option一次增加一个
parser.add_option("-q",action="store",type="string",dest="term",help="assign where predicate")
parser.add_option("-c","--column",action="store",type="string",dest="col",help="assign query column")
parser.add_option("-t",action="store",type="string",dest="table",help="assign query table")
parser.add_option("-f","--format",action="store_true",dest="format",help="-f must match up -o")
parser.add_option("-o",action="store",type="string",dest="outfile",help="assign output file")
#解析命令行
options,args = parser.parse_args()#把上述dest值赋给我们自定义的变量
table = options.table
column = options.col
term = options.term
format = options.format#实现动态读查询
statement = "select * from %s where %s like \'%s\'"%(table,column,term)
cur = conn.cursor()
cur.execute(statement)
results = cur.fetchall()#模拟 \G 输出形式
if format is True:columns_query = "describe %s"%(table)cur.execute(columns_query)heards = cur.fetchall()column_list = []for record in heards:column_list.append(record[0])output = ""count = 1for record in results:output = output + "************ %s row ************\n\n"%(count)for field_no in xrange(0, len(column_list)):output = output + column_list[field_no]+ ": " + str(record[field_no]) + "\n"output = output + "\n"count = count + 1
else:output = []for record in xrange(0,len(results)):output.append(results[record])output = \'\'.join(output)#把输出结果定向到指定文件
if options.outfile:outfile = options.outfilewith open(outfile,\'w\') as out:out.write(output)
else:print output#关闭游标与连接
conn.close()
cur.close()

By DataHacker

2014-2-5

Good Luck！