SELECT 'a' 'd' 'mi' 'n'; SELECT CONCAT('a', 'd', 'm', 'i', 'n'); SELECT CONCAT_WS('', 'a', 'd', 'm', 'i', 'n'); SELECT GROUP_CONCAT('a', 'd', 'm', 'i', 'n');
文件特权
如下查询能够帮助肯定给定用户的FILE权限。javascript
SELECT file_priv FROM mysql.user WHERE user = 'username'; --。须要root权限 mysql4/5
若是用户具备FILE权限,则能够读取文件。java
LOAD_FILE()
Examples:
SELECT LOAD_FILE('F:/wing.txt'); SELECT LOAD_FILE(0x463A2F77696E672E747874);