Python封装的访问MySQL数据库的类及DEMO

 # Filename：mysql_class.py
 # Author:Rain.Zen; Date: 2014-04-15

 import MySQLdb

 class MyDb:

     '''初始化[类似于构造函数]'''
     def __init__(self, host, user, password, charset = 'utf8'):
         self.host = host
         self.user = user
         self.password = password
         self.charset = charset
         try:
             self.conn = MySQLdb.connect(host = self.host, user = self.user, passwd = self.password, charset = self.charset)
             self.cur = self.conn.cursor()
         except MySQLdb.Error as e:
             print('MySQL Error %d: %s' % (e.args[0], e.args[1]))

     '''组合字符串'''
     def joinData(self, data, char = ','):
         return char.join(data)

     '''解析条件语句，参数类型[{dict}, 'AND|OR'] | {dict}'''
     def parseMap(self, condition) :
         if isinstance(condition, list) :
             dictMap = condition[0]
             logic = ' '+ condition[1] +' '
         else :
             dictMap = condition
             logic = ' AND '

         if isinstance(dictMap, dict) :
             for k, v in dictMap.items():
                 dictMap[k] = "`"+ k +"` = '"+ str(v) +"'"
             return self.joinData(dictMap.values(), logic)
         else :
             return '1 = 1'

     '''选择数据表'''
     def selectDb(self, db):
       try :
           self.conn.select_db(db)
       except MySQLdb.Error as e:
           print('MySQL Error %d: %s' % (e.args[0], e.args[1]))

     '''执行SQL语句'''
     def query(self, sql):
         try :
             return self.cur.execute(sql)
         except MySQLdb.Error as e:
             print 'MySQL Error: %s \nSQL: %s' % (e, sql)

     '''添加一条信息'''
     def addOne(self, table, dictData):
         for field, value in dictData.items():
             dictData[field] = "'"+ str(value) +"'"
         self.query('INSERT INTO ' + table + "("+ self.joinData(dictData.keys()) +') VALUES('+ self.joinData(dictData.values()) +')')
         return self.cur.lastrowid

     '''修改一条信息[根据条件]'''
     def saveOne(self, table, dictData, condition):
         for key, val in dictData.items():
             dictData[key] = "`"+ key +"` = '"+ str(val) +"'"
         save_sql = 'UPDATE ' + table + ' SET ' + self.joinData(dictData.values()) + ' WHERE ' + self.parseMap(condition)
         return self.query(save_sql)

     '''删除信息[根据条件]'''
     def deleteOne(self, table, condition):
         return self.query('DELETE FROM ' + table + ' WHERE ' + self.parseMap(condition))

     '''读取单条信息[根据条件]'''
     def fetchOne(self, tabel, condition, fields = '*', dataType = 0):
         field = isinstance(fields, list) and self.joinData(fields) or fields
         self.query('SELECT '+ field +' FROM ' + tabel + ' WHERE ' + self.parseMap(condition))
         tupleData = self.cur.fetchone()
         if dataType == 0 or fields == '*' :
             return tupleData
         else :
             dictData = {}
             n = 0
             for k in fields:
                 dictData[k] = tupleData[n]
                 n = n + 1
             return dictData

     '''读取多条信息[根据条件]'''
     def fetchSome(self, tabel, condition, fields = '*', dataType = 0):
         field = isinstance(fields, list) and self.joinData(fields) or fields
         self.query('SELECT '+ field +' FROM ' + tabel + ' WHERE ' + self.parseMap(condition))
         tupleData = self.cur.fetchall()
         count = self.cur.rowcount
         if count > 0:
             if dataType == 0 or fields == '*' :
                 return (int(count), tupleData)
             else :
                 listData = []
                 for row in tupleData:
                     dictData = {}
                     n = 0
                     for k in fields:
                         dictData[k] = row[n]
                         n = n + 1
                     listData.append(dictData)
                 return (int(count), listData)
         else:
             return False

     '''获取信息总数[根据条件]'''
     def getCount(self, tabel, condition = 0):
         where = isinstance(condition, dict) and ' WHERE ' + self.parseMap(condition) or ''
         self.query('SELECT 0 FROM ' + tabel + where)
         return self.cur.rowcount

     '''提交事务'''
     def commit(self):
         self.conn.commit()

     '''关闭句柄和连接'''
     def close(self):
         self.cur.close()
         self.conn.close()

DEMO

 # Filename: test_mysql.py

 from mysql_class import MyDb

 '''测试开始'''

 '''连接数据库[实例化]'''
 my_db = MyDb('127.0.0.1', 'python_user', '')

 '''选择数据库'''
 my_db.selectDb('test')

 '''修改单条信息
 dictData = {'class' : 'DD', 'name' : 'Pitt.C', 'subject' : 'Match_01', 'score' : 60}
 condition = [{'class' : 'DD', 'name' : 'Tom'}, 'OR']
 print my_db.saveOne('cla_info', dictData, condition)'''

 '''删除信息
 condition = [{'class':'DD', 'name':'bd', 'id':17}, 'OR']
 print my_db.deleteOne('cla_info', condition)'''

 '''获取单条信息
 fields = ['class', 'name', 'subject', 'score', 'comment']
 condition = {'id':6}
 print my_db.fetchOne('cla_info', condition, fields)'''

 '''新增[单条]
 dictData = {'class' : 'DDD', 'name' : 'Pitt', 'subject' : 'Match', 'score' : 97}
 in_id = my_db.addOne('cla_info', dictData)
 print 'Successful add data: ID(%d)' % in_id'''

 '''查询数据
 field = ['class', 'name', 'subject', 'score', 'comment']
 condition = {'name':'小明'}
 ary = my_db.fetchSome('cla_info', condition, field, 1)
 if ary or False :
     print 'The total is:',ary[0]
     print ary[1]'''

 '''获取总数
 condition = {'name':'小明'}
 print my_db.getCount('cla_info')'''

 '''事务处理'''
 my_db.commit()

 '''关闭句柄和连接'''
 my_db.close()