Very simple, but very practical

1. Use MySQL to import the query results to a file.

Mysql-umsg-PMSG message-e "select appkey from app"> 1.txt

2. when using runtime to call system commands, I encountered a problem. I want to compress a file, and the directory where this file is located is dynamically created. Zip is used for compression, the last two parameters fill in the absolute path name. It is found that the original directory will be exposed when the compressed file is decompressed. After thinking a lot of ways, we plan to call two commands. First, we enter the Directory and then compress the file, failed. Later, we can see that there are several examples of runtime.exec(partial logs. I did not take a look at them carefully, but I tried to write the compressed command to the relative path in runtime.exe C (CMD, null, directory. Done.