mysql命令行选项

Question

mysql中的命令行选项-e或--execute用于在shell提示符本身中执行命令。有没有办法打印错误如果查询没有成功（如果该号码，如果输出为零？） 就像

Empty set (0.89 sec) 

Answer 1

mysql已经默认打印出错误消息。如果发生错误，它也退出，退出代码大于0：

$ mysql -e "SHOW VARIABLES LIKE 'version' THIS WON'T WORK" 
ERROR 1064 (42000) at line 1: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'THIS WON'T WORK' at line 1 
$ echo $? 
1 
$ mysql -e "SHOW VARIABLES LIKE 'version'" 
+---------------+------------+ 
| Variable_name | Value  | 
+---------------+------------+ 
| version  | 5.5.19-log | 
+---------------+------------+ 
$ echo $? 
0