安装pymysql
pip install pymysql
2|0使用pymysql
2|1使用数据查询语句
查询一条数据fetchone()
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') """
查询多条数据fetchall()
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') """
更改游标的默认设置,返回值为字典
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'} """
返回一条数据时也是一样的。返回字典或者时元组看个人需要。
2|2使用数据操作语句
执行增加、删除、更新语句的操作其实是一样的。只写一个作为示范。
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()
和查询语句不同的是必须使用commit()提交事务,否则操作就是无效的。
3|0编写数据库连接类
普通版
MysqlHelper.py
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: <a>本文来源gao*daima.com搞@代#码&网6</a> 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()