最近被这两行代码折磨了两天，一直觉得从语法角度来说完全不存在问题，然而。。。。

上代码
错误示范

sql = "select * from user where user=" + request.args.get('user') + " and password="+ request.args.get('password')+ ""

sql = "INSERT INTO user(user, password) VALUES (" + request.args.get('user') + ", " + request.args.get('password') + ")"

正确代码

user=str(request.args.get('user'))
password=str(request.args.get('password'))
sql = "select * from user where user=  '%s'  and password= %s" % (user,password)

sql = "INSERT INTO user(user, password) VALUES ('%s','%s')"%(user,password)

错误示范只对数字有效而对字符串就显然无用了