14. Using the CUSTOMERS table, you need to generate a report that shows 50% of each credit amount in each income level. The report should NOT show any repeated credit amounts in each income level. Which query would give the required
1.异常概念: >>> a Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'a' is not defined #交互模式中,类似这种的便是异常 2.异常未处理程序终止运行 当异常出现的时候,且没有做任何处理,程序不会继续执行也就是程序被中断了. a print("ok") 运行结果: E