Oracle»¥»»×ܽá
Oracle»¥»»×ܽá
1. ¶àÐл»³ÉÒ»ÐÐ
col1 col2 col1 col2
a 1
a 2 ת»»ºó a 1,2,3
a 3
A.
sys_connect_by_path
º¯Êý
SELECT NAME, ltrim(MAX(sys_connect_by_path(userid, ',')), ',') userid
from(SELECT NAME, userid,row_number() over(PARTITION BY NAME ORDER BY userid) rn from test) START WITH rn = 1 CONNECT BY rn - 1 = PRIOR rn AND NAME = PRIOR NAME GROUP BY NAME ORDER BY NAME;
B.wmsys.WM_CONCATº¯Êý
select NAME,wmsys.WM_CONCAT(userid) from xj_class group by NAME;
2. Ò»Ðл»¶àÐÐ
col col
1,2,3 ת»»ºó 1
2
3
select substr(subjec
Ïà¹ØÎĵµ£º
Ëæ×Å΢ÈíÐÂÒ»´ú²Ù×÷ϵͳ Windows7 µÄÕýʽ·¢ÐУ¬Ê¹Óà Windows7 µÄÅóÓÑÒ²Ô½À´Ô½¶à£¬ºÜ¶àÈËÔÚ Windows7 »·¾³Ï°²×° Oracle »ò¶à»òÉÙÓöµ½ÁËһЩÎÊÌ⣬ÓеÄÉõÖÁ·¢³ö“Windows7ÎÞ·¨°²×°Oracle”µÄ¸Ð¿®¡£½ñÌì±ÊÕß½áºÏͼÎĺʹó¼Ò·ÖÏíÒ»ÏÂÔÚWindows7»·¾³ÏÂÈçºÎ³É¹¦°²×°OracleÊý¾Ý¿â¡£
&n ......
1.Ñ¡ÓÃÊʺϵÄOracleÓÅ»¯Æ÷
OracleµÄÓÅ»¯Æ÷¹²ÓÐ3ÖÖ£º
a.RULE(»ùÓÚ¹æÔò)
b.COST(»ùÓڳɱ¾)
c.CHOOSE(Ñ¡ÔñÐÔ)
ÉèÖÃȱʡµÄÓÅ»¯Æ÷£¬¿ÉÒÔͨ¹ý¶Ôinit.oraÎļþÖÐOPTIMIZER_MODE²ÎÊýµÄ
¸÷ÖÖÉùÃ÷£¬ÈçRULE¡¢COST¡¢CHOOSE¡¢ALL_ROWS¡¢FIRST_ROWS¡£Ä㵱ȻҲÔÚSQL¾ä¼¶»òÊǻỰ(session)¼¶¶ÔÆä½øÐи²
¸Ç¡£
ΪÁËʹÓûùÓڳɱ¾µÄÓÅ»¯Æ ......
¸ÅÊö
ÐéÄâרÓÃÊý¾Ý¿â (VPD) ÌṩÁ˽ÇÉ«ºÍÊÓͼÎÞ·¨ÌṩµÄÐм¶·ÃÎÊ¿ØÖÆ¡£¶ÔÓÚ»¥ÁªÍø·ÃÎÊ£¬ÐéÄâרÓÃÊý¾Ý¿â¿ÉÒÔÈ·±£ÔÚÏßÒøÐеĿͻ§Ö»ÄÜ¿´µ½ËûÃÇ×Ô¼ºµÄÕÊ»§¡£Web Íйܹ«Ë¾¿ÉÒÔÔÚͬһ Oracle Êý¾Ý¿âÖÐά»¤¶à¸ö¹«Ë¾µÄÊý¾Ý£¬µ«Ö»ÔÊÐíÿ¸ö¹«Ë¾²é¿´Æä×ÔÉíÊý¾Ý¡£
ÔÚÆóÒµÄÚ²¿£¬ÐéÄâÊý¾Ý¿â¿ÉÔÚÓ¦ÓóÌÐò²¿Êð·½Ãæ½µµÍÓµÓгɱ¾¡£¿ÉÒÔÔÚÊý ......
1.Ê×ÏÈ˵Ã÷һϣº
ÔÒòÊÇÒòΪÎÒÔÚ×öÕâ¸öÏîĿʱ£¬±»ÏÞÖÆµÃÌ«¶à£¬weblogicºÍoracleµÄ°æ±¾²»Äܱ䣬ҪʹÓÃÔÀ´µÄ°æ±¾¡£
Òò´ËÄØ¡£²Ù×÷ÆðÀ´±È½ÏÂé·³¡£¶øÇÒ²»Äܸü¸ÄÔ±¾¹¤³ÌÀïÃæµÄJar°ü£¨ËüÀïÃæ´æÔÚÁËoracle14.jar°ü£¬µ«±È½Ï¾É£©
weblogic°æ±¾Îª£º8.14
oracle°æ±¾Îª£º9i
2.ÔÚÕâÀïÄØ£¬Ê¹ÓÃhibernate£¬ÒÔÁ÷µÄÐÎʽ¶ÁÈ¡µ½Êý¾ÝÀïÃæ ......