python学习 第七篇 sql优化

>>> fields=["id","name","name_cn","email","mobile"]
>>> sql="select %s from users where name ='admin'" % ','.join(fields)
>>> sql
"select id,name,name_cn,email,mobile from users where name ='admin'"
>>> cur.execute(sql)
1L
>>> res=cur.fetchone()
>>> res
(16L, u'admin', u'admin', u'134556', u'123455')
>>> user={}
>>> for i,k in enumerate(fields):
...    user[k]=res[i]
...
>>> user
{'mobile': u'123455', 'email': u'134556', 'name_cn': u'admin', 'id': 16L, 'name': u'admin'}
>>> for i,k in enumerate(fields):
...     print i,k   i 是索引值，k是fields 里面的值
...
0 id
1 name
2 name_cn
3 email
4 mobile
>>> res[1]
u'admin'

>>> fields=["id","name","name_cn","email","mobile","role"]
>>> fields
['id', 'name', 'name_cn', 'email', 'mobile', 'role']
>>> sql="insert into users (%s) values ('fujinzhou','fujinzhou','144@qq.com','136**','ops')" % ','.join(fields)
>>> sql
"insert into users (id,name,name_cn,email,mobile,role) values ('fujinzhou','fujinzhou','144@qq.com','136**','ops')"

>>> fields=["name","name_cn","email","mobile","role"]
>>> data={"name":"fujinzhou"}
>>> data
{'name': 'fujinzhou'}
>>> data={"name":"fujinzhou","name_cn":"fujinzhou","email":"144@qq.com","mobile":"1122","role":"ops"}
>>> sql="insert into users (%s) values %s" %(','.join(fields),','.join(['"%s"' %data[k] for k in fields]))
>>> sql
'insert into users (name,name_cn,email,mobile,role) values "fujinzhou","fujinzhou","144@qq.com","1122","ops"'

>>> fields=[]
>>> values=[]
>>> data={"name":"fujinzhou","name_cn":"fujinzhou","email":"144@qq.com","mobile":"1122","role":"ops"}
>>> for k,v in data.items():
...     fields.append(k)
...     values.append("'%s'" % v)
...
>>> fields
['mobile', 'role', 'name_cn', 'name', 'email']
>>> values
["'1122'", "'ops'", "'fujinzhou'", "'fujinzhou'", "'144@qq.com'"]
>>> sql="insert into users (%s) values (%s)" %(','.join(fields),','.join(values))
>>> sql
"insert into users (mobile,role,name_cn,name,email) values ('1122','ops','fujinzhou','fujinzhou','144@qq.com')"