oracle 数据库的一些sql操作

时间字段查询的sql语句：

SELECT * FROM mycontent t WHERE t.create_date <= to_date('2010-06-21','yyyy-MM-dd')

修改时间字段的sql语句：

UPDATE MYCONTENT T

SET T.CREATE_DATE = TO_DATE('2012.05.28 13:10:45',

'yyyy-MM-dd hh24:mi:ss'),

T.MODIFY_DATE = TO_DATE('2012.05.28 13:10:45',

'yyyy-MM-dd hh24:mi:ss')

WHERE T.CONTENT_ID = '123456'

查询锁表情况的语句：

SELECT SESS.SID,

SESS.SERIAL#,

LO.ORACLE_USERNAME,

LO.OS_USER_NAME,

AO.OBJECT_NAME,

LO.LOCKED_MODE

FROM V$LOCKED_OBJECT LO, DBA_OBJECTS AO, V$SESSION SESS

WHERE AO.OBJECT_ID = LO.OBJECT_ID

AND LO.SESSION_ID = SESS.SID;

查询结果字符串相加：

SELECT * 'http://www.baidu.com/index.jsp?contentId=' || T.CONTENT_ID AS myLINK

FROM MYCONTENT T

递归查询显示：

SELECT REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(CATEGORY_CODE,

'1',

'0'),

'2',

'0'),

'3',

'0'),

'4',

'0'),

'5',

'0'),

'6',

'0'),

'7',

'0'),

'8',

'0'),

'9',

'0') || C.CATEGORY_NAME,

C.CATEGORY_CODE

FROM MYCATEGORY C

WHERE C.CATEGORY_CODE LIKE '001001%'

ORDER BY C.CATEGORY_CODE