Tag: 案例

内部mysql case语句未在结果中显示时不匹配

我有一个mysql语句如下 SELECT CASE WHEN HOUR(created_at) BETWEEN 0 AND 11 THEN ‘Morning’ WHEN HOUR(created_at) BETWEEN 12 AND 15 THEN ‘Afternoon’ WHEN HOUR(created_at) BETWEEN 16 AND 18 THEN ‘Evening’ WHEN HOUR(created_at) BETWEEN 19 AND 24 THEN ‘Night’ END AS session, SUM(total) AS `total` FROM `orders` WHERE (purchase_date between ‘2014-05-01’ and ‘2014-05-30’) GROUP BY CASE WHEN HOUR(created_at) BETWEEN […]

Ruby：将数组项传递给case语句

我试图将数组传递给case语句，以便我可以将数组元素作为命令读取。 不幸的是，似乎它没有工作，程序跳转到else语句。 def input_console() quit = 0 puts “Tell me what you want to do:” loop do print “\n >>> ” input = gets.chomp sentence = input.split case sentence when sentence[0] == “go” && sentence[1] == “to” puts sentence[2] when sentence[0] == “quit” quit = 1 else puts “No le entiendo Senor…” end break if […]

如何在“case when”中捕获Errno :: ECONNRESET类？

我的应用程序（Ruby 1.9.2）可能引发不同的exception，包括网络连接中断。 我rescue Exception => e ，然后做case/when以不同的方式处理它们，但是几个错误直接通过我的案例。 rescue Exception => e p e.class case e.class when Errno::ECONNRESET p 1 when Errno::ECONNRESET,Errno::ECONNABORTED,Errno::ETIMEDOUT p 2 else p 3 end end 打印： Errno::ECONNRESET 3