当insert语句失败并且错误代码在DECLARE EXIT handler语句中指定，那么控制将传递到处理程序，而过程将退出。
When the INSERT statement fails with the error code specified in the DECLARE exit handler statement, control passes to the handler, and the procedure is exited.
INSERT 错误将控制转移到 SQLSTATE 代码的退出处理程序。
The INSERT error transfers control to the exit handler for that SQLSTATE code.
如果这个异常没有被捕捉到，它将立即关闭应用程序，并将一条错误消息和栈跟踪输出到控制台。
If this exception isn't caught, it will immediately kill the application with an error message and stack trace dumped to the console.
应用推荐