Ò׽ؽØͼÈí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

sqlÓÅ»¯É¨Ã¤

1.oracleɨÃèµÄ˳ÐòΪ´Óϵ½ÉÏ£¬´ÓÓÒµ½×ó
           ËùÒÔÎÒÃÇÒª¾¡¿ÉÄܵİÑÊý¾ÝÉٵıí·ÅÔÚºóÃ棬½»²æ±í·ÅÔÚºóÃ棬×îÄܹýÂ˵ÄÌõ¼þ·ÅÔÚºóÃæ
2.²»ÒªÔÚË÷ÒýÉÏʹÓüÆËãºÍnot²Ù×÷·û
           Ë÷ÒýÒ»µ©²ÎÓë¼ÆËã»òʹÓÃÁËnot²Ù×÷·û£¬oracle½«»áºöÂÔÕâ¸öË÷Òý
3.¾¡Á¿Ê¹ÓÃinºÍand£¬¾¡Á¿±ÜÃâʹÓÃor£¬or»á²úÉú´óÁ¿µÄ¹ýÂË £¬Ö±½Óµ¼ÖÂÂß¼­¶Á´óÁ¿Ôö¼Ó
4.±ØҪʱʹÓÃautotrace(sqlplusÖÐÓÐЧ£¬PL/SQLÖÐÎÞЧ)
           ÃüÁset autotrace on;
           ¹æÔò£º¾¡Á¿¼õÉÙÂß¼­¶Á£¬Ó¦¸Ã±ÜÃâÎïÀí¶Á£¬Ìá¸ß»º³åÇøÃüÖÐÂÊ £¬×îºÃ±£³ÖÔÚ95%ÒÔÉÏ¡£
           recursive calls      µÝ¹éµ÷ÓÃ
           db block gets       Êý¾Ý¿é¶ÁÈ¡
           consistent gets    Ò»ÖÂÐÔ¶ÁÈ¡
           physical reads      ÎïÀí¶ÁÈ¡
           redo size              ²úÉúµÄÖØ×öÈÕÖ¾´óС
Âß¼­¶Á=consistent gets + db block gets
»º³åÇøÃüÖÐÂÊ=(Âß¼­¶Á-ÎïÀí¶Á)/Âß¼­¶Á
Ò»¸ö½ø³Ì¿ÉÄܶÔÒÔºóÄܹ»Êý¾Ý¿éÖжà¸ösession¡£
sqlÓÅ»¯×îÖس£ÓõÄÊÇ°ì·¨ÊÇ£ºÉóÊÓsqlÓï¾ä
Ò²¿ÉÒÔÖ´ÐÐÕâÌõsqlÀ´²éÕҷdz£ºÄ·Ñ¿Õ¼äµÄsql£º
select sql_text ,sharable_mem from v$sql where sharable_mem > '100000' order by sharable_mem ;


Ïà¹ØÎĵµ£º

select 1 from ... sqlÓï¾äÖеÄ1´ú±íʲôÒâ˼£¿

 select  1 from ...£¬ sqlÓï¾äÖеÄ1´ú±íʲôÒâ˼£¿²é³öÀ´ÊǸöʲô½á¹û£¿
        select 1 from table;Óëselect anycol(Ä¿µÄ±í¼¯ºÏÖеÄÈÎÒâÒ»ÐУ© from table;Óëselect * from table ´Ó×÷ÓÃÉÏÀ´ËµÊÇûÓвî±ðµÄ£¬¶¼ÊDz鿴ÊÇ·ñÓмǼ£¬Ò»°ãÊÇ×÷Ìõ¼þ²éѯÓõġ£select 1 from Ö ......

SQL ×Ö·û´®²ð·Ö

       ÓÐÕâÑùÒ»¸ö×Ö·û´®(ÖÐ,¹ú,ÖÐ,ÈËÃñ,¹ú,ÏÖ´ú¹¤Òµ»¯½ø³Ì,¹ú)
´¦Àí¹ýÖ®ºó±ä³É(ÖÐ,¹ú,ÈËÃñ,ÏÖ´ú¹¤Òµ»¯½ø³Ì)
 
        ÒÔÏÂÊÇÎҵķ½·¨,ÓÐʲô²»¶ÔµÄµØ·½»¹Çë¸÷λָµã
 ------------------ɾ³ýÖظ´µÄ×Ö·û
 declare
@v1 nvarchar
......

SQL SERVER2000´ò²¹¶¡ÎÊÌâ»ã×Ü

SQL SERVER2000´ò²¹¶¡ÎÊÌâ»ã×Ü ¡¾http://hi.baidu.com/yanhai/blog/item/cf67c2ce07a9f50992457e9d.html¡¿
SQL ServerµÄ²¹¶¡°æ±¾¼ì²é²»ÈçWindows ²¹¶¡°æ±¾¼ì²éÖ±½Ó£¬Ò»¸öϵͳ¹ÜÀíÔ±£¬Èç¹û²»Á˽âSQL Server°æ±¾¶ÔÓ¦µÄ²¹¶¡ºÅ£¬¿ÉÄÜÒ²»áÓöµ½Ò»µãÂé·³£¬Òò´ËÔÚÕâ˵Ã÷һϣ¬Í¨¹ýÕâÑùµÄ°ì·¨Åбð»úÆ÷ÊÇ°²È«µÄ°ì·¨£¬²»»á¶Ôϵͳ²úÉúÈ ......

ms sql ³£ÓòÙ×÷Óï¾ä

MS SQLµÄһЩ¾­µä³£ÓòÙ×÷Óï¾ä»ã×Ü  ¡¾http://hi.baidu.com/kychen88/blog/item/b3c8e7d960821b3c32fa1cee.html¡¿
1.°´ÐÕÊϱʻ­ÅÅÐò:
Select * from TableName Order By CustomerName Collate Chinese_PRC_Stroke_ci_as
2.Êý¾Ý¿â¼ÓÃÜ:
select encrypt('ԭʼÃÜÂë')
select pwdencrypt('ԭʼÃÜÂë')
select pwdcomp ......

SQL×Ö·û´®²Ù×÷º¯Êý´óÈ«

selectÓï¾äÖÐÖ»ÄÜʹÓÃsqlº¯Êý¶Ô×ֶνøÐвÙ×÷£¨Á´½Ósql server£©£¬
select ×Ö¶Î1 from ±í1 where ×Ö¶Î1.IndexOf("ÔÆ")=1;
ÕâÌõÓï¾ä²»¶ÔµÄÔ­ÒòÊÇindexof£¨£©º¯Êý²»ÊÇsqlº¯Êý£¬¸Ä³Ésql¶ÔÓ¦µÄº¯Êý¾Í¿ÉÒÔÁË¡£
left£¨£©ÊÇsqlº¯Êý¡£
select ×Ö¶Î1 from ±í1 where charindex£¨'ÔÆ',×Ö¶Î1£©=1;
×Ö·û´®º¯Êý¶Ô¶þ½øÖÆÊý¾Ý¡¢×Ö·û´®º ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØͼ | ¸ÓICP±¸09004571ºÅ