杂项 备用一下

原符号       <        <=      >       >=       &        '        "
替换符号    &lt;    &lt;=   &gt;    &gt;=   &amp;   &apos;  &quot;
第二种：
<![CDATA[ >= ]]>

select * from 'EMP' as of timestamp (systimestamp - interval '5' minute)

select to_char(sysdate,'yyyy-fmmm-dd') from dual;

SELECT TO_CHAR(时间戳的那一列 / (1000 * 60 * 60 * 24) +  
       TO_DATE('1970-01-01 08:00:00', 'YYYY-MM-DD HH:MI:SS'), 'YYYY-MM-DD HH:MI:SS') AS CDATE  
FROM 'EMP' ;

select scn_to_timestamp(ora_rowscn) stime from 'EMP'

select T.OWNER,T.OBJECT_NAME,T.OBJECT_TYPE,T.CREATED,T.LAST_DDL_TIME from ALL_OBJECTS t 
where t.object_name='EMP'

select T.OWNER,T.name,T.TYPE from all_dependencies t
where t.referenced_name='EMP'

select Utl_Raw.Cast_To_Raw(sys.dbms_obfuscation_toolkit.md5(input_string => 'adminadmin')) from dual

select 
decode(ABS(MOD(DBMS_RANDOM.RANDOM,2)),1,'男','女')  as gender
from dual;

select to_date(trunc(dbms_random.value(2449354,2451186)),'J')  from dual;

SELECT REPLACE('XX省XX市XX区XX路141号'
              ,REGEXP_SUBSTR('XX省XX市XX区XX路141号'
                            ,'[0-9]+'
                            ,1
                            ,1)
              ,ABS(MOD(DBMS_RANDOM.RANDOM, 200)))
FROM DUAL T;