python3+ 连接并操作mysql 数据库,支持读写分离
最近，看了关于的一篇帖子，关于python的，决定花几天看下python的基本知识。看了基础知识后，发现记不住，就随手写了点代码，加深自己的记忆。
暂时主要写了对数据库的操作，其他的都还没有做，后续会逐步完善，代码写的很基础，里面肯定还存在很多问题，自己保存起，怕后面丢失了。
主要是 pyMysql库 实现了对mysql数据库的操作，目前支持读写分离。
1、app_db.py对数据库的配置。 支持读写分离。
def dbconfig() :
config = dict();
config['master'] = {
"write" : {
'host' : 'localhost',
'dbuser' : 'root',
'dbpwd' : '',
'port' : 3306,
'dbname' : 'liuyan',
'dbprefix' : 'ly_',
},
"read" : {
'host': 'localhost',
'dbuser': 'root',
'dbpwd': '',
'port': 3306,
'dbname': 'liuyan',
'dbprefix': 'ly_',
}
};
config['server'] = {
"write": {
'host': 'localhost',
'dbuser': 'root',
'dbpwd': '',
'port': 3306,
'dbname': 'liuyanben',
'dbprefix': 't_',
},
"read": {
'host': 'localhost',
'dbuser': 'root',
'dbpwd': '',
'port': 3306,
'dbname': 'liuyanben',
'dbprefix': 't_',
}
};
return config;
2、app_db.py 实现对数据库的操作，支持读写分离。
#@author SteveGao
import sys;
import pymysql;
import random;
from config.app_db import dbconfig;
class DB :
link = dict();
_res = '';
_mode = "read";# write,read
_dbconfig = dbconfig();
_host = '';
def __init__(self,host = "master"):
self._host = host;
def connect(self,mode = "read"):
try :
self._mode = mode;
self._dbconfig = self._dbconfig[self._host][self._mode];
self.host = self._dbconfig['host'];
self.dbuser = self._dbconfig['dbuser'];
self.password = self._dbconfig['dbpwd'];
self.dbname = self._dbconfig['dbname'];
self.port = self._dbconfig['port'];
self._res = pymysql.cursors.DictCursor;
self.link[self._host] = pymysql.connect(self.host,self.dbuser,self.password,self.dbname,self.port);
except Exception as err:
print("DBERR数据库连接失败： \n[%s]" %(err));
exit();
def getTableName(self,tableName):
return self._dbconfig['dbprefix'] + tableName;
'''
查询单张表的一条记录
'''
def getOne(self,tableName,id):
try :
self.connect('read');
tableName = self.getTableName(tableName);
cursors = self.link[self._host].cursor(self._res);
sql = "SELECT * FROM %s WHERE id = %d LIMIT 1";
cursors.execute(sql %(tableName,int(id)));
result = cursors.fetchone();
return result;
except Exception as err:
print("DBERR数据库查询单条记录失败： \n[%s]" % (err));
exit();
'''
根据条件查询单表的内容
'''
def getCondition(self,tableName, condition = ''):
try :
self.connect('read');
cursors = self.link[self._host].cursor(self._res);
tableName = self.getTableName(tableName);
if (condition):
sql = "SELECT * FROM %s WHERE %s";
cursors.execute(sql % (tableName, condition));
else :
sql = "SELECT * FROM %s;";
cursors.execute(sql % (tableName));
result = cursors.fetchall();
result = list(result);
return result;
except Exception as err:
print("DBERR数据库按条件查询记录失败： \n[%s]" % (err));
exit();
'''
根据SQL语句查询
'''
def executeSql(self,sql,findOne = 'm'):
try :
sql = sql.lstrip();
if (len(sql) == 0):
return False;
operate = sql[0:6].upper();
if (operate == "SELECT"):
self._mode = 'read';
elif (operate == 'INSERT' or operate == "UPDATE" or operate == 'DELETE') :
self._mode = 'write';
else :
self._mode = 'write';
self.connect(self._mode);
cursors = self.link[self._host].cursor(self._res);
execs = cursors.execute(sql);
if (operate == "SELECT") :
if ((findOne == 'm') and ("LIMIT 1" not in sql.upper())) :
result = cursors.fetchall();
else :
result = cursors.fetchone();
return result;
else :
return execs;
except Exception as err:
print("DBERR数据库执行失败： \n[%s]" % (err));
exit();
'''
使用字典插入单条数据
link = DB('localhost','root','','liuyan');
data = {"user_name":"stevegao","password" : "444444",'create_time':"2017-02-12 09:12:12", 'login_times' : "1"};
link.insertAll('ly_user',data);
'''
def insert(self,table,data):
try :
self.connect('write');
table = self.getTableName(table);
tinsert = "INSERT INTO %s";
fieldList = ' (';
valueList = ' (';
for field in data :
fieldList += "`" + field + "`,";
valueList += '"' + data[field] + '",';
fieldList = fieldList[0:-1] + ") ";
valueList = valueList[0:-1] + ") ";
sql = tinsert + fieldList + "values " + valueList;
cursors = self.link[self._host].cursor(self._res);
insert = cursors.execute(sql %(table));
print(sql %(table));
#self.link.commit();
return insert;
except Exception as err :
self.link.rollback();
print("DBERR数据库插入单条记录失败：\n[%s]" % (err));
exit();
'''
使用字典，批量插入数据到数据库
link = DB('localhost','root','','liuyan');
data = dict();
data[0] = {"user_name":"stevegao","password" : "444444",'create_time':"2017-02-12 09:12:12", 'login_times' : "1"};
data[1] = {"user_name":"jennygao","password" : "555555",'create_time':"2017-02-12 09:12:12", 'login_times' : "1"};
ii = link.insertAll('ly_user',data);
'''
def insertAll(self,table,data):
try :
self.connect('write');
table = self.getTableName(table);
tinsert = "INSERT INTO %s";
fieldList = ' (';
values = '';
oneField = data[0];
for field in oneField:
fieldList += "`" + field + "`,";
fieldList = fieldList[0:-1] + ") ";
for row in data :
valueList = '(';
for field in data[row] :
valueList += '"' + data[row][field] + '",';
values += valueList[0:-1] + "),";
sql = tinsert + fieldList + "values " + values[0:-1];
cursors = self.link[self._host].cursor(self._res);
insert = cursors.execute(sql %(table));
#self.link.commit();
return insert;
except Exception as err:
self.link.rollback();
print("DBERR数据库批量插入记录失败：\n[%s]" % (err));
exit();
def commit(self):
self.link[self._host].commit();
def rollback(self):
self.link[self._host].rollback();
'''
关闭数据库链接
'''
def close(self):
self.link[self._host].close();
#@author SteveGao
from gyk.database.app_db import DB;
from config.app_db import dbconfig;
'''
向数据库插入单条数据
model = Model();
data = {"user_name":"stevegao","password" : "444444",'create_time':"2017-02-12 09:12:12", 'login_times' : "1"};
insert = model.table('ly_user').insert(data);
if (insert) :
model.db.link.commit(); //提交事务
else :
model.db.link.rollback(); //回滚事务
'''
class Model :
lastsql = '';
_wherestr = '';
_orderstr = '';
_groupstr = '';
_limitstr = '';
_fieldstr = '';
_tablename = '';
_having = '';
_host = "";
db = {};
def __init__(self,host = "master"):
self._host = host;
mysql = DB(host.lower()); #实例化数据库类
self.db[self._host] = mysql;
def max(self,field):
sql = self._parseStatis('max',field);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def min(self,field):
sql = self._parseStatis('min',field);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def avg(self,field):
sql = self._parseStatis('avg',field);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def count(self,field):
sql = self._parseStatis('count',field);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def sum(self,field):
sql = self._parseStatis('sum',field);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def table(self,tablename):
pconfig = dbconfig();
prefix = pconfig[self._host]['write']['dbprefix'];
self._tablename = "`" + prefix + tablename + "`";
return self;
def where(self,where = ""):
if (where) :
self._wherestr = self._parseWhereDict(where);
else :
self._wherestr = where;
return self;
def orderBy(self,order = ""):
self._orderstr = order;
return self;
def groupBy(self,groupby = ""):
self._groupstr = groupby;
return self;
def having(self,having = ""):
self._having = having;
return self;
def limit(self,limit = ""):
self._limitstr = limit;
return self;
def field(self,field = "*"):
self._fieldstr = field;
return self;
def select(self):
sql = self._parseQuery();
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def find(self):
sql = self._parseQuery(1);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql,'s');
return result;
def query(self,sql):
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
'''
插入单条数据，data类型为字典型
'''
def insert(self,data):
sql = self._parseInsert(data);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
'''
批量插入数据，data类型为字典型
'''
def insertAll(self,data):
sql = self._parseInsertAll(data);
if (sql == False) :
return sql;
self.lastsql = sql;
result = self.db[self._host].executeSql(sql);
return result;
def delete(self):
sql = self._parseDelete();
self.lastsql = sql;
result = self.db[self._host].executeSql(sql, 's');
return result;
def update(self,data):
sql = self._parseSetDict(data);
self.lastsql = sql;
result = self.db[self._host].executeSql(sql, 's');
return result;
'''
提交事务
'''
def commit(self):
self.db[self._host].commit();
'''
提交回滚
'''
def rollback(self):
self.db[self._host].rollback();
'''
解析查询语句
'''
def _parseQuery(self,limit = 2):
tempsql = "";
tempsql = "SELECT ";
if (self._fieldstr) :
tempsql += self._fieldstr;
else :
tempsql += "*";
tempsql += " FROM ";
if (self._tablename) :
tempsql += self._tablename;
if (self._wherestr):
tempsql += " WHERE ";
tempsql += self._wherestr;
tempsql += " ";
if (self._groupstr):
tempsql += " GROUP BY ";
tempsql += self._groupstr;
if (self._having) :
tempsql += " HAVING ";
tempsql += self._having;
if (self._orderstr):
tempsql += " ORDER BY ";
tempsql += self._orderstr;
tempsql += " ";
if (limit == 2) :
if (self._limitstr):
tempsql += " LIMIT ";
tempsql += self._limitstr;
else :
tempsql += " LIMIT 1";
return tempsql;
def _parseInsert(self,data):
tinsert = "";
tinsert += "INSERT INTO ";
if (self._tablename) :
tinsert += self._tablename;
fieldList = ' (';
valueList = ' (';
for field in data:
fieldList += "`" + field + "`,";
valueList += '"' + data[field] + '",';
fieldList = fieldList[0:-1] + ") ";
valueList = valueList[0:-1] + ") ";
sql = tinsert + fieldList + "values " + valueList;
return sql;
def _parseInsertAll(self,data):
if (data.get(0) == None) :
return False;
tinsert = "";
tinsert += "INSERT INTO ";
if (self._tablename) :
tinsert += "`" +self._tablename + "`";
fieldList = ' (';
values = '';
oneField = data[0];
for field in oneField:
fieldList += "`" + field + "`,";
fieldList = fieldList[0:-1] + ") ";
for row in data:
valueList = '(';
for field in data[row]:
valueList += '"' + data[row][field] + '",';
values += valueList[0:-1] + "),";
sql = tinsert + fieldList + "VALUES " + values[0:-1];
return sql;
'''
解析查询语句
'''
def _parseStatis(self,func,field):
tempsql = "";
tempsql = "SELECT ";
if (field):
tempsql += func +"(" + field +")";
else:
tempsql += func +"(" + 1 +")";
tempsql += " FROM ";
if (self._tablename):
tempsql += self._tablename;
if (self._wherestr):
tempsql += " WHERE ";
tempsql += self._wherestr;
tempsql += " ";
if (self._groupstr):
tempsql += " GROUP BY ";
tempsql += self._groupstr;
if (self._having) :
tempsql += " HAVING ";
tempsql += self._having;
if (self._orderstr):
tempsql += " ORDER BY ";
tempsql += self._orderstr;
tempsql += " ";
if (self._groupstr == "") :
tempsql += " LIMIT 1";
return tempsql;
def _parseDelete(self):
tempsql = "";
tempsql = "DELETE ";
tempsql += " FROM ";
if (self._tablename):
tempsql += self._tablename;
if (self._wherestr):
tempsql += " WHERE ";
tempsql += self._wherestr;
tempsql += " ";
if (self._orderstr):
tempsql += " ORDER BY ";
tempsql += self._orderstr;
tempsql += " ";
if (self._limitstr):
tempsql += " LIMIT ";
tempsql += self._limitstr;
return tempsql;
def _parseUpdate(self,data):
if (not data) :
return False;
tempsql = "";
tempsql = "UPDATE ";
if (self._tablename):
tempsql += self._tablename;
tempsql += " SET ";
tempsql += self._parseDict(data);
if (self._wherestr):
tempsql += " WHERE ";
tempsql += self._wherestr;
tempsql += " ";
if (self._orderstr):
tempsql += " ORDER BY ";
tempsql += self._orderstr;
tempsql += " ";
if (self._limitstr):
tempsql += " LIMIT ";
tempsql += self._limitstr;
return tempsql;
def _parseSetDict(self,data):
result = "";
if (isinstance(data, dict)):
temp = "";
for field in data :
temp += '`' + field + '` = "' + data[field] + '",';
result = temp[0:-1];
else :
result = data;
return result;
def _parseWhereDict(self,data):
result = "";
if (isinstance(data, dict)):
temp = "";
for field in data :
temp += '`' + field + '` = "' + data[field] + '" AND ';
result = temp.rstrip()[0:-3];
else :
result = data;
return result;