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

ms sqlµ½mysqlµÄÒÆÖ²£º¹ØÓÚÊý¾ÝÀàÐÍÒÆÖ²µÄһЩÎÊÌâ

   ms sqlÖеÄintÐÍĬÈÏÊÇ4룬mysqlµÄintÐÍĬÈÏÊÇ11λ£¬Ç°Õßµ½ºóÕßµÄÒÆÖ²²»»áÓÐʲôÒþ»¼£¬µ«ÊǺóÕßµ½Ç°ÕßµÄÒÆÖ²¾Í´æÔÚλÊý²»¹»£¬²»ÄÜ´æ´¢´óÊýµÄÒþ»¼¡£
   »¹ÓÐbigint£¬ms sqlÊÇ8룬mysqlĬÈÏÊÇ20λ¡£


Ïà¹ØÎĵµ£º

sql ²é±í¿Õ¼äÓï¾ä

SELECT UPPER(F.TABLESPACE_NAME) "±í¿Õ¼äÃû",
       D.TOT_GROOTTE_MB "±í¿Õ¼ä´óС(M)",
       D.TOT_GROOTTE_MB - F.TOTAL_BYTES "ÒÑʹÓÿռä(M)",
       TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_G ......

SQL·ÖÒ³·½·¨

±íÖÐÖ÷¼ü±ØÐëΪ±êʶÁУ¬[ID] int IDENTITY (1,1)
Ò²¿ÉÒÔʹÓÃÁªºÏÖ÷¼ü id+id2+id3+……
 
1.·ÖÒ³·½°¸Ò»£º(ÀûÓÃNot InºÍSELECT TOP·ÖÒ³)
Óï¾äÐÎʽ£º  
SELECT TOP 10 *
from TestTable
WHERE (ID NOT IN
          (SELECT TOP 20 id
&nb ......

MySQLÊý¾Ý¿â»·¾³Ê¹ÓÃÈ«¹ý³Ì

Ô­ÎĵØÖ·£ºhttp://blog.csdn.net/wenjava/archive/2009/06/11/4261299.aspx
ÔÚʹÓÃMySQL֮ǰ£¬ÐèÒª½¨Á¢Êý¾Ý¿âµÄ»·¾³À´´´½¨Êý¾Ý±í£¬Ê×ÏÈÎÒÃÇÐèÒª°²×°¸ÃÊý¾Ý¿â»·¾³£¬¼´MySQL¡£
1¡¢ÏÂÔØMySQL
MySQLµÄ¹Ù·½ÍøÕ¾ÊÇhttp://www.mysql.org/£¬Èçͼ2-9Ëùʾ£º
ͼ2-9  MySQL¹Ù·½ÍøÕ¾
µ±Ç°Îȶ¨°æ±¾Îª5.1£¬ÎÒÃÇÑ¡ÓÃMySQL 5.1.22× ......

mysql explainÖеÄusing filesort

Using filesort±íʾÔÚË÷ÒýÖ®Í⣬ÐèÒª¶îÍâ½øÐÐÍⲿµÄÅÅÐò¶¯×÷¡£µ¼Ö¸ÃÎÊÌâµÄÔ­ÒòÒ»°ãºÍorder byÓÐÕßÖ±½Ó¹Øϵ£¬Ò»°ã¿ÉÒÔͨ¹ýºÏÊʵÄË÷ÒýÀ´¼õÉÙ»òÕß±ÜÃâ¡£
explain SELECT * from table_item WHERE user_id = 2 ORDER BY item_id LIMIT 0, 5
user_id ºÍ item_id ·Ö±ð½¨Á¢Ò»¸öË÷Òý£¬¶Ô´ËÓï¾äMySQLÑ¡ÔñÁË user_idË÷Òý£¬ÄÇô ite ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØͼ | ¸ÓICP±¸09004571ºÅ