python操作mysql数据库基本类封装

# -*- coding: UTF-8 -*-
import re
import MySQLdb as mdb

class MysqldbHelper(object):
"""操作mysql数据库，基本方法

"""
def __init__(self , host="localhost", username="root", password="", port=3306, database="test"):
self.host = host
self.username = username
self.password = password
self.database = database
self.port = port
self.con = None
self.cur = None
try:
self.con = mdb.connect(host=self.host, user=self.username, passwd=self.password, port=self.port, db=self.database)
# 所有的查询，都在连接 con 的一个模块 cursor 上面运行的
self.cur = self.con.cursor()
except:
raise "DataBase connect error,please check the db config."
def close(self):
"""关闭数据库连接

"""
if not  self.con:
self.con.close()
else:
raise "DataBase doesn't connect,close connectiong error;please check the db config."
def getVersion(self):
"""获取数据库的版本号

"""
self.cur.execute("SELECT VERSION()")
return self.getOneData()

def getOneData(self):
# 取得上个查询的结果，是单个结果
data = self.cur.fetchone()
return data

def creatTable(self, tablename, attrdict, constraint):
"""创建数据库表

args：
tablename  ：表名字
attrdict   ：属性键值对,{'book_name':'varchar(200) NOT NULL'...}
constraint ：主外键约束,PRIMARY KEY(`id`)
"""
if self.isExistTable(tablename):
return
sql = ''
sql_mid = '`id` bigint(11) NOT NULL AUTO_INCREMENT,'
for attr,value in attrdict.items():
sql_mid = sql_mid + '`'+attr + '`'+' '+ value+','
sql = sql + 'CREATE TABLE IF NOT EXISTS %s ('%tablename
sql = sql + sql_mid
sql = sql + constraint
sql = sql + ') ENGINE=InnoDB DEFAULT CHARSET=utf8'
print 'creatTable:'+sql
self.executeCommit(sql)

def executeSql(self,sql=''):
"""执行sql语句，针对读操作返回结果集

args：
sql  ：sql语句
"""
try:
self.cur.execute(sql)
records = self.cur.fetchall()
return records
except mdb.Error,e:
error = 'MySQL execute failed! ERROR (%s): %s' %(e.args[0],e.args[1])
print error

def executeCommit(self,sql=''):
"""执行数据库sql语句，针对更新,删除,事务等操作失败时回滚

"""
try:
self.cur.execute(sql)
self.con.commit()
except mdb.Error, e:
self.con.rollback()
error = 'MySQL execute failed! ERROR (%s): %s' %(e.args[0],e.args[1])
print "error:", error
return error

def insert(self, tablename, params):
"""创建数据库表

args：
tablename  ：表名字
key        ：属性键
value      ：属性值
"""
key = []
value = []
for tmpkey, tmpvalue in params.items():
key.append(tmpkey)
if isinstance(tmpvalue, str):
value.append("\'" + tmpvalue + "\'")
else:
value.append(tmpvalue)
attrs_sql = '('+','.join(key)+')'
values_sql = ' values('+','.join(value)+')'
sql = 'insert into %s'%tablename
sql = sql + attrs_sql + values_sql
print '_insert:'+sql
self.executeCommit(sql)

def select(self, tablename, cond_dict='', order='', fields='*'):
"""查询数据

args：
tablename  ：表名字
cond_dict  ：查询条件
order      ：排序条件

example：
print mydb.select(table)
print mydb.select(table, fields=["name"])
print mydb.select(table, fields=["name", "age"])
print mydb.select(table, fields=["age", "name"])
"""
consql = ' '
if cond_dict!='':
for k, v in cond_dict.items():
consql = consql+k + '=' + v + ' and'
consql = consql + ' 1=1 '
if fields == "*":
sql = 'select * from %s where ' % tablename
else:
if isinstance(fields, list):
fields = ",".join(fields)
sql = 'select %s from %s where ' % (fields, tablename)
else:
raise "fields input error, please input list fields."
sql = sql + consql + order
print 'select:' + sql
return self.executeSql(sql)

def insertMany(self,table, attrs, values):
"""插入多条数据

args：
tablename  ：表名字
attrs        ：属性键
values      ：属性值

example：
table='test_mysqldb'
key = ["id" ,"name", "age"]
value = [[101, "liuqiao", "25"], [102,"liuqiao1", "26"], [103 ,"liuqiao2", "27"], [104 ,"liuqiao3", "28"]]
mydb.insertMany(table, key, value)
"""
values_sql = ['%s' for v in attrs]
attrs_sql = '('+','.join(attrs)+')'
values_sql = ' values('+','.join(values_sql)+')'
sql = 'insert into %s'% table
sql = sql + attrs_sql + values_sql
print 'insertMany:'+sql
try:
print sql
for i in range(0,len(values),20000):
self.cur.executemany(sql,values[i:i+20000])
self.con.commit()
except mdb.Error,e:
self.con.rollback()
error = 'insertMany executemany failed! ERROR (%s): %s' %(e.args[0],e.args[1])
print error

def delete(self, tablename, cond_dict):
"""删除数据

args：
tablename  ：表名字
cond_dict  ：删除条件字典

example：
params = {"name" : "caixinglong", "age" : "38"}
mydb.delete(table, params)

"""
consql = ' '
if cond_dict!='':
for k, v in cond_dict.items():
if isinstance(v, str):
v = "\'" + v + "\'"
consql = consql + tablename + "." + k + '=' + v + ' and '
consql = consql + ' 1=1 '
sql = "DELETE FROM %s where%s" % (tablename, consql)
print sql
return self.executeCommit(sql)

def update(self, tablename, attrs_dict, cond_dict):
"""更新数据

args：
tablename  ：表名字
attrs_dict  ：更新属性键值对字典
cond_dict  ：更新条件字典

example：
params = {"name" : "caixinglong", "age" : "38"}
cond_dict = {"name" : "liuqiao", "age" : "18"}
mydb.update(table, params, cond_dict)

"""
attrs_list = []
consql = ' '
for tmpkey, tmpvalue in attrs_dict.items():
attrs_list.append("`" + tmpkey + "`" + "=" +"\'" + tmpvalue + "\'")
attrs_sql = ",".join(attrs_list)
print "attrs_sql:", attrs_sql
if cond_dict!='':
for k, v in cond_dict.items():
if isinstance(v, str):
v = "\'" + v + "\'"
consql = consql + "`"
a843
+ tablename +"`." + "`" + k + "`" + '=' + v + ' and '
consql = consql + ' 1=1 '
sql = "UPDATE %s SET %s where%s" % (tablename, attrs_sql, consql)
print sql
return self.executeCommit(sql)

def dropTable(self, tablename):
"""删除数据库表

args：
tablename  ：表名字
"""
sql = "DROP TABLE  %s" % tablename
self.executeCommit(sql)

def deleteTable(self, tablename):
"""清空数据库表

args：
tablename  ：表名字
"""
sql = "DELETE FROM %s" % tablename
self.executeCommit(sql)

def isExistTable(self, tablename):
"""判断数据表是否存在

args：
tablename  ：表名字

Return:
存在返回True，不存在返回False
"""
sql = "select * from %s" % tablename
result = self.executeCommit(sql)
if result is None:
return True
else:
if re.search("doesn't exist", result):
return False
else:
return True

if __name__ == "__main__":
mydb = MysqldbHelper()
print mydb.getVersion()
table='test_mysqldb'
attrs={'name':'varchar(200) DEFAULT NULL','age':'int(11) DEFAULT NULL'}
constraint='PRIMARY KEY(`id`)'
print mydb.creatTable(table, attrs, constraint)
params = {"name" : "caixinglong", "age" : "38"}
mydb.insert('test_mysqldb', params)
print mydb.select(table)
print mydb.select(table, fields=["name", "age"])
print mydb.select(table, fields=["age", "name"])
key = ["id" ,"name", "age"]
value = [[101, "liuqiao", "25"], [102,"liuqiao1", "26"], [103 ,"liuqiao2", "27"], [104 ,"liuqiao3", "28"]]
mydb.insertMany(table, key, value)
mydb.delete(table, params)
cond_dict = {"name" : "liuqiao", "age" : "18"}
mydb.update(table, params, cond_dict)
# mydb.deleteTable(table)
# mydb.dropTable(table)
print mydb.select(table+ "1")
print mydb.isExistTable(table+ "1")