hibernate mysql ´æ´¢¶þ½øÖÆÎļþÎÊÌâ×ܽá
ÏÈ˵Ã÷Ò»ÏÂBlobµÄÀàÐÍ£¬Ö±½Ó´ÓÍøÉÏÕª³ÁË£¡£¡£¡
1¡¢MySQLÓÐËÄÖÖBLOBÀàÐÍ:
¡¡¡¡·tinyblob:½ö255¸ö×Ö·û
¡¡¡¡·blob:×î´óÏÞÖÆµ½65K×Ö½Ú
¡¡¡¡·mediumblob:ÏÞÖÆµ½16M×Ö½Ú
¡¡¡¡·longblob:¿É´ï4GB
2¡¢³ýÁËÀàÐͶԺóÃæ´æÈ¡Îļþ´óСÓÐÏÞÖÆ£¬»¹ÒªÐÞ¸ÄmysqlµÄÅäÖÃÎļþ¡£
¡¡¡¡Windows¡¢linux»ù±¾Ò»Ñùͨ¹ýÐÞ¸ÄÎļþmy.ini»òmy.cnfÎļþ£¬ÔÚÎļþÖÐÔö¼Ó max_allowed_packet=10M£¨¾ÍÊÇ×î´ó10M£¬mysqlĬÈÏËÆºõ1MB£¬Ôö¼ÓǰÏȲéÕÒÒ»ÏÂÈ·±£Ã»ÓÐÉèÖùý£©
3¡¢×öÁËÒÔÉÏÉèÖúó£¬Èç¹ûÉÏ´«½Ï´óÒ»µãÎļþʱ»òÕßijЩÎļþʱ»¹Êdzö´í£¬È籨һЩÂÒÂ룬¹À¼Æ¾ÍÊÇÏÂÃæµÄÎÊÌâÁË¡£
Êý¾Ý¿â»ò±íµÄ×Ö·û¼¯ÎÊÌ⣬ÈçhibernateÁ¬½ÓʹÓÃutf-8£¬±íÊÇgbkµÈ£¬Ò»°ãÖ»ÒªÉèÖÃhibernateÖÐÊý¾ÝÁ¬½Ó²¿·Ö¾ÍÐУ¬Èç
jdbc:mysql://192.168.0.4:3306/test?useUnicode=true&characterEncoding=UTF-8
Ïà¹ØÎĵµ£º
¼¸¸ö³£ÓÃÓÃÀý£º
1.µ¼³öÕû¸öÊý¾Ý¿â mysqldump -u Óû§Ãû -p Êý¾Ý¿âÃû > µ¼³öµÄÎļþÃû mysqldump -u wcnc -p smgp_apps_wcnc > wcnc.sql2.µ¼³öÒ»¸ö±í mysqldump -u Óû§Ãû -p Êý¾Ý¿âÃû ±íÃû> µ¼³öµÄÎļþÃû mysqldump -u wcnc -p smgp_apps_wcnc users> wcnc_users.sql3.µ¼³öÒ»¸öÊý¾Ý¿â½ ......
1.¶Ô²éѯ½øÐÐÓÅ»¯£¬Ó¦¾¡Á¿±ÜÃâÈ«±íɨÃ裬Ê×ÏÈÓ¦¿¼ÂÇÔÚ where ¼° order by Éæ¼°µÄÁÐÉϽ¨Á¢Ë÷Òý¡£
2.Ó¦¾¡Á¿±ÜÃâÔÚ where ×Ó¾äÖжÔ×ֶνøÐÐ null ÖµÅжϣ¬·ñÔò½«µ¼ÖÂÒýÇæ
·ÅÆúʹÓÃË÷Òý¶ø½øÐÐÈ«±íɨÃ裬È磺
select id from t where num is null
¿ÉÒÔÔÚnumÉÏÉèÖÃ
ĬÈÏÖµ0£¬È·±£±íÖÐnumÁÐûÓÐnullÖµ£¬È»ºóÕâ
Ñù²éѯ£º
sel ......
mysqlÊý¾Ý¿âlimit²éѯÓÅ»¯
MYSQLµÄÓÅ»¯ÊǷdz£ÖØÒªµÄ¡£ÆäËû×î³£ÓÃÒ²×îÐèÒªÓÅ»¯µÄ¾ÍÊÇlimit¡£mysqlµÄlimit¸ø·ÖÒ³´øÀ´Á˼«´óµÄ·½±ã£¬µ«Êý¾ÝÁ¿Ò»´óµÄʱºò£¬limitµÄÐÔÄܾͼ±¾çϽµ¡£
ͬÑùÊÇÈ¡10ÌõÊý¾Ý
select * from yanxue8_visit limit 10000,10 ºÍ
select * from yanxue8_visit limit 0,10
¾Í²»ÊÇÒ»¸öÊýÁ¿¼¶±ðµ ......
InnoDB,ÆÕͨµÄmysql
dump±¸·ÝÏÂÀ´,mysql»Ö¸´ÆðÀ´ÂýµÃÒª
ËÀ.
ÓÚÊÇÍøÉÏÕÒÁ˺þÃ,²ÅÕÒµ½Õâô¸ö¹¤¾ß
.
http://launchpad.net/percona-xtrabackup/release-1.2/release-1.2/+download/xtrabackup-1.2.tar.gz
ÏȲâÊÔÏÂÔÙ˵.
¿ÉÒÔÕâô±¸·Ý:
MyISAM
񡜧
/usr/local/mysql/bin/mysqldump -uyejr -pyejr
--default-char ......
mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!
[root@localhost]# mysql -u root -p
Enter password:
ERROR 2002 (H ......