Article Outline
Python mysql example 'python-mysql-util'
Modules used in program:
import mysql.connector.errorsimport mysql.connector
python python-mysql-util
Python mysql example: python-mysql-util
FIND_BY_SQL = "findBySql" # 根据sql查找
COUNT_BY_SQL = "countBySql" # 自定义sql 统计影响行数
INSERT = "insert" # 插入
UPDATE_BY_ATTR = "updateByAttr" # 更新数据
DELETE_BY_ATTR = "deleteByAttr" # 删除数据
FIND_BY_ATTR = "findByAttr" # 根据条件查询一条记录
FIND_ALL_BY_ATTR = "findAllByAttr" #根据条件查询多条记录
COUNT = "count" # 统计行
EXIST = "exist" # 是否存在该记录
import mysql.connector
import mysql.connector.errors
from common.customConst import Const
class MySQLet:
"""Connection to a MySQL"""
# def __init__(self,user='',password='',database='',charset=None,port=3306):
def __init__(self,**kwargs):
try:
self._conn = mysql.connector.connect(host=kwargs["host"], user=kwargs["user"], password=kwargs["password"],
charset=kwargs["charset"], database=kwargs["database"], port=kwargs["port"])
self.__cursor = None
print("连接数据库")
#set charset charset = ('latin1','latin1_general_ci')
except mysql.connector.errors.ProgrammingError as err:
print('mysql连接错误：' + err.msg)
# def findBySql(self, sql, params={}, limit=0, join='AND'):
def findBySql(self, **kwargs):
"""
自定义sql语句查找
limit = 是否需要返回多少行
params = dict(field=value)
join = 'AND | OR'
"""
cursor = self.__getCursor()
# sql = self.__joinWhere(kwargs["sql"], kwargs["params"], kwargs["join"])
if kwargs.get("join", 0) == 0: kwargs["join"] = "AND"
sql = self.__joinWhere(**kwargs)
cursor.execute(sql, tuple(kwargs["params"].values()))
rows = cursor.fetchmany(size=kwargs["limit"]) if kwargs["limit"] > 0 else cursor.fetchall()
result = [dict(zip(cursor.column_names,row)) for row in rows] if rows else None
return len(result)
# def countBySql(self,sql,params = {},join = 'AND'):
def countBySql(self, **kwargs):
"""自定义sql 统计影响行数"""
if kwargs.get("join", 0) == 0: kwargs["join"] = "AND"
cursor = self.__getCursor()
# sql = self.__joinWhere(kwargs["sql"], kwargs["params"], kwargs["join"])
sql = self.__joinWhere(**kwargs)
cursor.execute(sql, tuple(kwargs["params"].values()))
result = cursor.fetchall() # fetchone是一条记录， fetchall 所有记录
return len(result) if result else 0
# def insert(self,table,data):
def insert(self, **kwargs):
"""新增一条记录
table: 表名
data: dict 插入的数据
"""
fields = ','.join('`'+k+'`' for k in kwargs["data"].keys())
values = ','.join(("%s", ) * len(kwargs["data"]))
sql = 'INSERT INTO `%s` (%s) VALUES (%s)' % (kwargs["table"], fields, values)
cursor = self.__getCursor()
cursor.execute(sql, tuple(kwargs["data"].values()))
insert_id = cursor.lastrowid
self._conn.commit()
return insert_id
# def updateByAttr(self,table,data,params={},join='AND'):
def updateByAttr(self, **kwargs):
# """更新数据"""
if kwargs.get("params", 0) == 0:
kwargs["params"] = {}
if kwargs.get("join", 0) == 0:
kwargs["join"] = "AND"
fields = ','.join('`' + k + '`=%s' for k in kwargs["data"].keys())
values = list(kwargs["data"].values())
values.extend(list(kwargs["params"].values()))
sql = "UPDATE `%s` SET %s " % (kwargs["table"], fields)
kwargs["sql"] = sql
sql = self.__joinWhere(**kwargs)
cursor = self.__getCursor()
cursor.execute(sql, tuple(values))
self._conn.commit()
return cursor.rowcount
# def updateByPk(self,table,data,id,pk='id'):
def updateByPk(self, **kwargs):
"""根据主键更新，默认是id为主键"""
return self.updateByAttr(**kwargs)
# def deleteByAttr(self,table,params={},join='AND'):
def deleteByAttr(self, **kwargs):
"""删除数据"""
if kwargs.get("params", 0) == 0:
kwargs["params"] = {}
if kwargs.get("join", 0) == 0:
kwargs["join"] = "AND"
# fields = ','.join('`'+k+'`=%s' for k in kwargs["params"].keys())
sql = "DELETE FROM `%s` " % kwargs["table"]
kwargs["sql"] = sql
# sql = self.__joinWhere(sql, kwargs["params"], kwargs["join"])
sql = self.__joinWhere(**kwargs)
cursor = self.__getCursor()
cursor.execute(sql, tuple(kwargs["params"].values()))
self._conn.commit()
return cursor.rowcount
# def deleteByPk(self,table,id,pk='id'):
def deleteByPk(self, **kwargs):
"""根据主键删除，默认是id为主键"""
return self.deleteByAttr(**kwargs)
# def findByAttr(self,table,criteria = {}):
def findByAttr(self, **kwargs):
"""根據條件查找一條記錄"""
return self.__query(**kwargs)
# def findByPk(self,table,id,pk='id'):
def findByPk(self, **kwargs):
return self.findByAttr(**kwargs)
# def findAllByAttr(self,table,criteria={}, whole=true):
def findAllByAttr(self, **kwargs):
"""根據條件查找記錄"""
return self.__query(**kwargs)
# def count(self,table,params={},join='AND'):
def count(self, **kwargs):
"""根据条件统计行数"""
if kwargs.get("join", 0) == 0: kwargs["join"] = "AND"
sql = 'SELECT COUNT(*) FROM `%s`' % kwargs["table"]
# sql = self.__joinWhere(sql, kwargs["params"], kwargs["join"])
kwargs["sql"] = sql
sql = self.__joinWhere(**kwargs)
cursor = self.__getCursor()
cursor.execute(sql, tuple(kwargs["params"].values()))
result = cursor.fetchone()
return result[0] if result else 0
# def exist(self,table,params={},join='AND'):
def exist(self, **kwargs):
"""判断是否存在"""
return self.count(**kwargs) > 0
def close(self):
"""关闭游标和数据库连接"""
if self.__cursor is not None:
self.__cursor.close()
self._conn.close()
def __getCursor(self):
"""获取游标"""
if self.__cursor is None:
self.__cursor = self._conn.cursor()
return self.__cursor
# def __joinWhere(self,sql,params,join):
def __joinWhere(self, **kwargs):
"""转换params为where连接语句"""
if kwargs["params"]:
keys,_keys = self.__tParams(**kwargs)
where = ' AND '.join(k+'='+_k for k,_k in zip(keys,_keys)) if kwargs["join"] == 'AND' else ' OR '.join(k+'='+_k for k,_k in zip(keys,_keys))
kwargs["sql"]+=' WHERE ' + where
return kwargs["sql"]
# def __tParams(self,params):
def __tParams(self, **kwargs):
keys = ['`'+k+'`' for k in kwargs["params"].keys()]
_keys = ['%s' for k in kwargs["params"].keys()]
return keys,_keys
# def __query(self,table,criteria,whole=False):
def __query(self, **kwargs):
if kwargs.get("whole", False) == False or kwargs["whole"] is not True:
kwargs["whole"] = False
kwargs["criteria"]['limit'] = 1
# sql = self.__contact_sql(kwargs["table"], kwargs["criteria"])
sql = self.__contact_sql(**kwargs)
cursor = self.__getCursor()
cursor.execute(sql)
rows = cursor.fetchall() if kwargs["whole"] else cursor.fetchone()
result = [dict(zip(cursor.column_names, row)) for row in rows] if kwargs["whole"] else dict(zip(cursor.column_names, rows)) if rows else None
return result
# def __contact_sql(self,table,criteria):
def __contact_sql(self, **kwargs):
sql = 'SELECT '
if kwargs["criteria"] and type(kwargs["criteria"]) is dict:
#select fields
if 'select' in kwargs["criteria"]:
fields = kwargs["criteria"]['select'].split(',')
sql+= ','.join('`'+field+'`' for field in fields)
else:
sql+=' * '
#table
sql+=' FROM `%s`'% kwargs["table"]
#where
if 'where' in kwargs["criteria"]:
sql+=' WHERE '+ kwargs["criteria"]['where']
#group by
if 'group' in kwargs["criteria"]:
sql+=' GROUP BY '+ kwargs["criteria"]['group']
#having
if 'having' in kwargs["criteria"]:
sql+=' HAVING '+ kwargs["criteria"]['having']
#order by
if 'order' in kwargs["criteria"]:
sql+=' ORDER BY '+ kwargs["criteria"]['order']
#limit
if 'limit' in kwargs["criteria"]:
sql+=' LIMIT '+ str(kwargs["criteria"]['limit'])
#offset
if 'offset' in kwargs["criteria"]:
sql+=' OFFSET '+ str(kwargs["criteria"]['offset'])
else:
sql+=' * FROM `%s`'% kwargs["table"]
return sql
def findKeySql(self, key ,**kwargs):
sqlOperate = {
Const.COUNT: lambda: self.count(**kwargs),
Const.COUNT_BY_SQL: lambda: self.countBySql(**kwargs),
Const.DELETE_BY_ATTR: lambda: self.deleteByAttr(**kwargs),
Const.EXIST: lambda: self.exist(**kwargs),
Const.FIND_ALL_BY_ATTR: lambda: self.findAllByAttr(**kwargs),
Const.INSERT: lambda: self.insert(**kwargs),
Const.FIND_BY_ATTR: lambda: self.findByAttr(**kwargs),
Const.UPDATE_BY_ATTR: lambda: self.updateByAttr(**kwargs),
Const.FIND_BY_SQL: lambda: self.findBySql(**kwargs)
}
return sqlOperate[key]()
if __name__ == "__main__":
mysqlet = MySQLet(host="127.0.0.1", user="root", password="", charset="utf8", database="userinfo", port=3306)
# 根据字段统计count, join>>AND,OR,可以不传，默认为AND
print(mysqlet.findKeySql(Const.COUNT, table="info", params={"id": "11", "name": "666"}, join="OR"))
# 自定义sql语句统计count
print(mysqlet.findKeySql(Const.COUNT_BY_SQL, sql="select * from info", params={"name": "666"}, join="AND"))
#插入数据
print(mysqlet.findKeySql(Const.INSERT, table="info", data={"name":"333", "pwd": "111"}))
#根据字段删除,不传params参数，就是删除全部
print(mysqlet.findKeySql(Const.DELETE_BY_ATTR, table="info", params={"id": 20}))
# 查找是否存在该记录,不传params参数，就是查找全部.join同上
print(mysqlet.findKeySql(Const.EXIST, table="info", params={"id": 180},join='AND'))
#根据字段查找多条记录，whole不传就查一条记录，criteria里面可以传where,group by,having,order by,limt,offset
print(mysqlet.findKeySql(Const.FIND_ALL_BY_ATTR, table="info", criteria= {"where": "name=333"}, whole=True))
# 根据字段查一条记录，和上面的查多条记录参数基本一样，少了个whole参数
print(mysqlet.findKeySql(Const.FIND_BY_ATTR, table="info", criteria= {"where": "name=333"}))
# 根据字段更新数据库中的记录，join可以传AND,OR,不传默认取AND
print(mysqlet.findKeySql(Const.UPDATE_BY_ATTR, table="info",data={"name": "-09"}, params={"id": 18, "name": "333"}, join='AND'))
# 根据自定义sql语句查询记录，limit:0表示所有记录，join：AND|OR.不传取AND
print(mysqlet.findKeySql(Const.FIND_BY_SQL, sql="select * from info", params={"name": "333", "id": 18}, limit=0))
Python links
- Learn Python: https://pythonbasics.org/
- Python Tutorial: https://pythonprogramminglanguage.com