BLOBת»»ÎªCLOBµÄº¯Êý£¨oracleÖÐÖ´ÐУ©
BLOBת»»ÎªCLOBµÄº¯Êý£¨oracleÖÐÖ´ÐУ©
CREATE OR REPLACE FUNCTION BlobToClob(blob_in IN BLOB) RETURN CLOB AS
v_clob CLOB;
v_varchar VARCHAR2(32767);
v_start PLS_INTEGER := 1;
v_buffer PLS_INTEGER := 32767;
BEGIN
DBMS_LOB.CREATETEMPORARY(v_clob, TRUE);
FOR i IN 1 .. CEIL(DBMS_LOB.GETLENGTH(blob_in) / v_buffer) LOOP
v_varchar := UTL_RAW.CAST_TO_VARCHAR2(DBMS_LOB.SUBSTR(blob_in,
v_buffer,
v_start));
DBMS_LOB.WRITEAPPEND(v_clob, LENGTH(v_varchar), v_varchar);
DBMS_OUTPUT.PUT_LINE(v_varchar);
v_start := v_start + v_buffer;
END LOOP;
RETURN v_clob;
END BlobToClob;
Ò»¡¢ BLOBºÍCLOBµÄÇø±ð
1. BLOBʹÓöþ½øÖƱ£´æÊý¾Ý£¬CLOBʹÓÃCHARÀ´±£´æÊý¾Ý¡£
2. CLOB£¬NCLOB£¬BLOB¶¼ÊÇÄÚ²¿µÄLOB(Large Object)ÀàÐÍ£¬×4G£¬Òª±£´æÍ¼Æ¬¡¢Îı¾Îļþ¡¢WordÎļþ×îºÃʹÓÃBLOBÀàÐÍ¡£
¶þ¡¢ ³£ÓòÙ×÷£º
Get£¨£©·½·¨£º
CLOB£º
//»ñµÃÊý¾Ý¿âÁ¬½Ó
Connection con = ConnectionFactory.getConnection(); &n
Ïà¹ØÎĵµ£º
LENGTH calculates length using characters as defined by the input character set.
LENGTHB uses bytes instead of characters.
VSIZE returns the number of bytes in the internal representation of expr.
LENGTHC uses Unicode complete characters.
LENGTH2 uses UCS2 codepoints.
......
Ò»¡¢ ROWIDµÄ¸ÅÄî
¡¡¡¡´æ´¢
ÁËrowÔÚÊý¾ÝÎļþÖеľßÌåλÖãº64λ±àÂëµÄÊý¾Ý£¬A-Z, a-z, 0-9, +, ºÍ /£¬
¡¡¡¡rowÔÚÊý¾Ý¿éÖеĴ洢
·½Ê½
¡¡¡¡SELECT ROWID, last_name from hr.employees WHERE department_id = 20;
¡¡¡¡±ÈÈ磺OOOOOOFFFBBBBBBRRR
¡¡¡¡OOOOOO£ºdata object number, ¶ÔÓ¦dba_objects.data_object_id
¡¡¡ ......
Ê×ÏȲéÕÒÄ¿±êÓû§µÄµ±Ç°½ø³Ì£º
select sid,serial# from v$session where username='ERP';
²éѯ½á¹û£º
sid serial#
222 123
122 233
Ç¿ÐжϿªÓû§Á¬½Ó£º
alter system kill session 'sid,serial';
ÀýÈ磺
alter system kill session '222,123';
......
1.¾ø¶ÔÖµ
S:select abs(-1) value
O:select abs(-1) value from dual
2.È¡Õû(´ó)
S:select ceiling(-1.001) value
O:select ceil(-1.001) value from dual
3.È¡Õû£¨Ð¡£©
S:select floor(-1.001) value
O:select floor(-1.001) value from dual
4.È ......
http://hi.baidu.com/firefly5002/blog/item/5b5719fcb5bd3e1d08244d11.html
Oracle 10G DataGuard
server A: 10.85.10.44 SID=mesdb
target server B: 10.85.10.43
oracle version:10.2.0.1
OS platform : windows 2003
Data GuardĬÈÏÊÇmaximize performance£¬ ¿ÉÒÔÓÃÒÔÏÂÓï¾äÀ´½øÐÐģʽ¼äµÄÇл»¡£
ALTER DATABASE ......