做搜索引擎优化对网站有哪些好处大型网站开发实战
oracle col命令可以对列进行进行格式化,格式:col 列名 for(mat) 格式
例如:
col owner for a100 设置owner列格式
col 列名:显示当前列的格式
SQL> col owner
COLUMN	 owner ON
FORMAT	 a100
SQL> 
 
clear column:清除所有列的格式
SQL> col owner for a100;
SQL> col owner
COLUMN	 owner ON
FORMAT	 a100
SQL> clear column;
columns 已清除
SQL> col owner
SP2-0046: COLUMN 'owner' 未定义
SQL> 
 
host hostname:查看主机名
SQL> host hostname
patrolagentSQL> 
 
help index:帮助
SQL> help index;Enter Help [topic] for help.@             COPY         PAUSE                    SHUTDOWN@@            DEFINE       PRINT                    SPOOL/             DEL          PROMPT                   SQLPLUSACCEPT        DESCRIBE     QUIT                     STARTAPPEND        DISCONNECT   RECOVER                  STARTUP