关于pymysql模块的使用以及代码详解

 from pymysql import * conn = connect( host='127.0.0.1', port=3306, user='root', password='123456', database='itcast', charset='utf8') # 创建游标 c = conn.cursor() # 执行sql语句 c.execute("select * from student") # 查询一行数据 result = c.fetchone() print(result) # 关闭游标 c.close() # 关闭数据库连接 conn.close() """ (1, '张三', 18, b'\x01') """

 from pymysql import * conn = connect( host='127.0.0.1', port=3306, user='root', password='123456', database='itcast', charset='utf8') # 创建游标 c = conn.cursor() # 执行sql语句 c.execute("select * from student") # 查询多行数据 result = c.fetchall() for item in result: print(item) # 关闭游标 c.close() # 关闭数据库连接 conn.close() """ (1, '张三', 18, b'\x01') (2, '李四', 19, b'\x00') (3, '王五', 20, b'\x01') """

 from pymysql import * conn = connect( host='127.0.0.1', port=3306, user='root', password='123456', database='itcast', charset='utf8') # 创建游标，操作设置为字典类型 c = conn.cursor(cursors.DictCursor) # 执行sql语句 c.execute("select * from student") # 查询多行数据 result = c.fetchall() for item in result: print(item) # 关闭游标 c.close() # 关闭数据库连接 conn.close() """ {'id': 1, 'name': '张三', 'age': 18, 'sex': b'\x01'} {'id': 2, 'name': '李四', 'age': 19, 'sex': b'\x00'} {'id': 3, 'name': '王五', 'age': 20, 'sex': b'\x01'} """

 from pymysql import * conn = connect( host='127.0.0.1', port=3306, user='root', password='123456', database='itcast', charset='utf8') # 创建游标 c = conn.cursor() # 执行sql语句 c.execute("insert into student(name,age,sex) values (%s,%s,%s)",("小二",28,1)) # 提交事务 conn.commit() # 关闭游标 c.close() # 关闭数据库连接 conn.close()

 from pymysql import connect,cursors class MysqlHelper: def __init__(self, host="127.0.0.1", user="root", password="123456", database="itcast", charset='utf8', port=3306): self.host = host self.port = port self.user = user self.password = password self.database = database self.charset = charset self._conn = None self._cursor = None def _open(self): # print("连接已打开") self._conn = connect(host=self.host, port=self.port, user=self.user, password=self.password, database=self.database, charset=self.charset) self._cursor = self._conn.cursor(cursors.DictCursor) def _close(self): # print("连接已关闭") self._cursor.close() self._conn.close() def one(self, sql, params=None): result: tuple = None try: self._open() self._cursor.execute(sql, params) result = self._cursor.fetchone() except Exception as e: print(e) finally: self._close() return result def all(self, sql, params=None): result: tuple = None try: self._open() self._cursor.execute(sql, params) result = self._cursor.fetchall() except Exception as e: print(e) finally: self._close() return result def exe(self, sql, params=None): try: self._open() self._cursor.execute(sql, params) self._conn.commit() except Exception as e: print(e) finally: self._close()

 from MysqlHelper import * mysqlhelper = MysqlHelper() ret = mysqlhelper.all("select * from student") for item in ret: print(item) """ {'id': 1, 'name': '张三', 'age': 18, 'sex': b'\x01'} {'id': 2, 'name': '李四', 'age': 19, 'sex': b'\x00'} {'id': 3, 'name': '王五', 'age': 20, 'sex': b'\x01'} {'id': 5, 'name': '小二', 'age': 28, 'sex': b'\x01'} {'id': 6, 'name': '娃哈哈', 'age': 28, 'sex': b'\x01'} {'id': 7, 'name': '娃哈哈', 'age': 28, 'sex': b'\x01'} """

 from pymysql import connect, cursors class DB: def __init__(self, host='localhost', port=3306, db='itcast', user='root', passwd='123456', charset='utf8'): # 建立连接 self.conn = connect( host=host, port=port, db=db, user=user, passwd=passwd, charset=charset) # 创建游标，操作设置为字典类型 self.cur = self.conn.cursor(cursor=cursors.DictCursor) def __enter__(self): # 返回游标 return self.cur def __exit__(self, exc_type, exc_val, exc_tb): # 提交数据库并执行 self.conn.commit() # 关闭游标 self.cur.close() # 关闭数据库连接 self.conn.close()

 from mysql_with import DB with DB() as db: db.execute("select * from student") ret = db.fetchone() print(ret) """ {'id': 1, 'name': '张三', 'age': 18, 'sex': b'\x01'} """