pymysql
pymysql基本使用
# 导入pymysql模块 import pymysql # 连接database conn = pymysql.connect( host=“你的数据库地址”, user=“用户名”,password=“密码”, database=“数据库名”, charset=“utf8”) # 得到一个可以执行SQL语句的光标对象 cursor = conn.cursor() # 执行完毕返回的结果集默认以元组显示 # 得到一个可以执行SQL语句并且将结果作为字典返回的游标 #cursor = conn.cursor(cursor=pymysql.cursors.DictCursor) # 定义要执行的SQL语句 sql = """ CREATE TABLE USER1 ( id INT auto_increment PRIMARY KEY , name CHAR(10) NOT NULL UNIQUE, age TINYINT NOT NULL )ENGINE=innodb DEFAULT CHARSET=utf8; #注意:charset='utf8' 不能写成utf-8 """ # 执行SQL语句 cursor.execute(sql) # 关闭光标对象 cursor.close() # 关闭数据库连接 conn.close()
插入单条数据
import pymysql conn =pymysql.connect( host ='192.168.0.103', port = 3306, user = 'root', password ='123', database ='xing', charset ='utf8' ) cursor =conn.cursor() #获取一个光标 sql ='insert into userinfo (user,pwd) values (%s,%s);' name = 'wuli' pwd = '123456789' cursor.execute(sql, [name, pwd]) conn.commit() cursor.close() conn.close()
添加多条数据
import pymysql conn = pymysql.connect( host='192.168.0.103', port=3306, user='root', password='123', database='xing', charset='utf8' ) # 获取一个光标 cursor = conn.cursor() # 定义要执行的sql语句 sql = 'insert into userinfo(user,pwd) values(%s,%s);' data = [ ('july', '147'), ('june', '258'), ('marin', '369') ] # 拼接并执行sql语句 cursor.executemany(sql, data) # 涉及写操作要注意提交 conn.commit() # 关闭连接 cursor.close() conn.close()
获取最新插入数据 (最后一条)
import pymysql # 建立连接 conn = pymysql.connect( host="192.168.0.103", port=3306, user="root", password="123", database="xing", charset="utf8" ) # 获取一个光标 cursor = conn.cursor() # 定义将要执行的SQL语句 sql = "insert into userinfo (user, pwd) values (%s, %s);" name = "wuli" pwd = "123456789" # 并执行SQL语句 cursor.execute(sql, [name, pwd]) # 涉及写操作注意要提交 conn.commit() # 关闭连接 # 获取最新的那一条数据的ID last_id = cursor.lastrowid print("最后一条数据的ID是:", last_id) cursor.close() conn.close()
删除操作
import pymysql # 建立连接 conn = pymysql.connect( host="192.168.0.103", port=3306, user="root", password="123", database="xing", charset="utf8" ) # 获取一个光标 cursor = conn.cursor() # 定义将要执行的SQL语句 sql = "delete from userinfo where user=%s;" name = "june" # 拼接并执行SQL语句 cursor.execute(sql, [name]) # 涉及写操作注意要提交 conn.commit() # 关闭连接 cursor.close() conn.close()
查询数据
import pymysql conn = pymysql.connect ( host='192.168.0.103', port=3306, user='root', password='123', database='xing', charset='utf8' ) # 获取一个光标 cursor = conn.cursor(cursor=pymysql.cursors.DictCursor) # 返回字典数据类型 # 定义将要执行的sql语句 sql = 'select user,pwd from userinfo;' # 拼接并执行sql语句 cursor.execute(sql) # 取到查询结果 ret1 = cursor.fetchone() # 取一条 ret2 = cursor.fetchmany(3) # 取三条 ret3 = cursor.fetchone() # 取一条 cursor.close() conn.close() print(ret1) print(ret2) print(ret3) 1 2 3 4 5 6 # 可以获取指定数量的数据 cursor.fetchmany(3) # 光标按绝对位置移动1 cursor.scroll(1, mode="absolute") # 光标按照相对位置(当前位置)移动1 cursor.scroll(1, mode="relative")
数据回滚
import pymysql # 建立连接 conn = pymysql.connect( host="192.168.0.103", port=3306, user="root", password="123", database="xing", charset="utf8" ) # 获取一个光标 cursor = conn.cursor() # 定义将要执行的SQL语句 sql1 = "insert into userinfo (user, pwd) values (%s, %s);" sql2 = "insert into hobby (id, hobby) values (%s,%s);" user = "july1" pwd = "july1" id = "我是错误的id" #id = "3" hobby = "打游戏" try: # 拼接并执行SQL语句 cursor.execute(sql1, [user, pwd]) print(sql1) cursor.execute(sql2, [id, hobby]) # 报错的SQL语句 # 涉及写操作注意要提交 conn.commit() except Exception as e: print(str(e)) # 有异常就回滚 conn.rollback() # 关闭连接 cursor.close() conn.close()