mysql Ò»µÀСÌâ
±íÃûΪtableµÄ±íÄÚÈÝÈçÏÂ
Year month value
2009 1 1.1
2009 2 1.2
2009 3 1.3
2009 4 1.4
2010 1 2.1
2010 2 2.2
2010 3 2.3
2010 4 2.4
ÒªÇó²éѯ½á¹ûΪ
year m1 m2 m3 m4
2009 1.1 1.2 1.3 1.4
2010 2.1 2.2 2.3 2.4
mysql> select year,sum(case when month=1 then value end) as 'm1',sum(case when m
onth=2 then value end) as 'm2',sum(case when month=3 then value end)as 'm3' from
table2 group by year;
Ïà¹ØÎĵµ£º
ĿǰÓв»ÉÙAMP£¨Apache\MySQL\PHP£©µÄ¼¯³ÉÈí¼þ£¬¿ÉÒÔÈÃÎÒÃÇÒ»´Î°²×°²¢ÉèÖúá£Õâ¶ÔÓÚ²»ÊìϤAMPµÄÓû§À´Ëµ£¬ºÃ´¦¶à¶à¡£
Ò»¡¢Ê¹ÓÃAMP¼¯³ÉÈí¼þµÄÓŵ㣺
1¡¢¿É±ÜÃâÓÉÓÚȱ·¦AMPµÄ֪ʶ£¬¶øÎÞ·¨ÕýÈ·ÉèÖû·¾³£»
2¡¢¿É¿ìËÙ°²×°²¢ÉèÖúÃAMP»·¾³£¬ÈÃÎÒÃÇÖ±½Ó¿ªÊ¼ÕæÕý¸ÐÐËȤµÄÈí¼þ£¬Èçxoops£»
3¡¢¿É·½±ãµÄ´î½¨²âÊÔ»·¾³£¬¶ÔÓÚ² ......
´Óhttp://hackmysql.com/mysqlslaÏÂÔØmysqlsla£¬µ±Ç°×îаæÎª£º2.03
tar zxvf mysqlsla-2.03.tar.gz
cp mysqlsla-2.03/bin/mysqlsla /usr/local/bin
Èç¹ûÌáʾ“Can’t locate DBI.pm”£¬Ö´ÐÐÒÔÏÂÃüÁî
yum install perl-DBI perl-DBD-MySQL -y
Õâʱ¾Í¿ÉÒÔʹÓÃmysqlslaÁË£¬Ó÷¨ÈçÏÂ
mysqlsla -lt slo ......
MySQLÊý¾Ý¿âµÄ¼òµ¥²Ù×÷
Ò».´´½¨Êý¾Ý¿â ͨ¹ýshow databases;ÃüÁîÏÔʾËùÓÐÒÑ´´½¨µÄÊý¾Ý¿âµÄÃû³Æ¡£
ͨ¹ýcreate database XXX;´´½¨Êý¾Ý¿âÃûΪXXXµÄÊý¾Ý¿â¡£ ÀýÈ磺mysql>create database test; ¶þ.´´½¨±íµ¥ ͨ¹ýcreate table XXX();´´½¨ ÀýÈç: È»ºó¿ÉÒÔͨ¹ýdescÃüÁî²é¿´±íµ¥: ÀýÈç: Èý ......
Õë¶Ôselect * from table where col1 > number order by col2 desc¡£
Æäʵ°´ÕÕ³£¹æµÄ·½·¨¿ÉÒÔÕâÑùÉè¼Æ£ºkey(col1, col2)
µ«ÊÇÕâÖÖ°ì·¨ÔÚmysqlÀï²»ËãÊÇÀíÏëµÄ£¬whereÌõ¼þÀïÏÞ¶¨Ë÷Òýǰ²¿·ÖÊÇÒ»¸ö·¶Î§µÄÇé¿öϺóÃæµÄorder by»¹ÊÇ»áÓÐfilesort¡£Èç¹ûwhereÌõ¼þÀïÏÞ¶¨Ë÷Òýǰ²¿·ÖÊÇÒ»¸ö³£Á¿£¬ÄÇôorder by¾Í»áÓÐЧÀûÓÃË÷Òý¡£À ......