import pymysql # conn = pymysql.connect(host=‘127.0.0.1‘, # user=‘root‘, # password="root", # database=‘homework‘) # cur = conn.cursor(cursor=pymysql.cursors.DictCursor) # 查询返回字典 # cur = conn.cursor() # cursor游标 # cur.execute(‘select * from student;‘) # print(cur.rowcount) # 获取查出多少行,便于使用fetchone取所有结果 # for i in range(cur.rowcount): # ret = cur.fetchone() # 获取一条结果 # print(ret) # # try: # cur.execute(‘select * from student;‘) # ret = cur.fetchone() # 获取一条结果 # print(ret) # ret2 = cur.fetchmany(10) # 获取多条结果 # print(ret2) # ret3 = cur.fetchall() # 获取全部结果 # print(ret3) # except pymysql.err.ProgrammingError as e: # print(e) # cur.close() # conn.close() # 增加 删除 修改 conn = pymysql.connect(host=‘127.0.0.1‘, user=‘root‘, password="123", database=‘homework‘) cur = conn.cursor() # cursor游标 try: # cur.execute(‘insert into student values(18,"男",3,"大壮")‘) # cur.execute(‘update student set gender = "女" where sid = 17‘) cur.execute(‘delete from student where sid = 17‘) conn.commit() except Exception as e: print(e) conn.rollback() # 可以试一下 myisam cur.close() conn.close() # # # # 实际操作mysql的时候会遇到的一个问题 # # # # 结合数据库 和python 写一个登录 # user = input(‘username :‘) # pwd = input(‘password :‘) # conn = pymysql.connect(host=‘127.0.0.1‘, # user=‘root‘, # password="123", # database=‘day42‘) # sql = ‘select * from userinfo where user = %s and password = %s‘ # cur = conn.cursor() # cur.execute(sql,(user,pwd)) # print(cur.fetchone()) # sql注入 # select * from userinfo where user = "1869" or 1=1;-- " and password = "3714";
# D:\python_22\day42\tmp.sql
# 表和数据的备份
# 备份数据 在cmd命令行直接执行
# mysqldump -uroot -p123 -h127.0.0.1 homework > D:\python_22\day42\tmp.sql
# 恢复数据 在mysql中执行命令
# 切换到一个要备份的数据库中
# source D:\python_22\day42\tmp.sql
# 备份库
# 备份
# mysqldump -uroot -p123 --databases homework > D:\python_22\day42\tmp2.sql
# 恢复
# source D:\python_22\day42\tmp2.sql
原文：https://www.cnblogs.com/shaohuagu/p/12318053.html