Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

MySQLµÄdatetimeÉèÖõ±Ç°Ê±¼äΪĬÈÏÖµ


MySQLµÄdatetimeÉèÖõ±Ç°Ê±¼äΪĬÈÏÖµ 
ÓÉÓÚMySQLĿǰ×ֶεÄĬÈÏÖµ²»Ö§³Öº¯Êý£¬ËùÒÔÓÃ
create_time datetime default now()
µÄÐÎʽÉèÖÃĬÈÏÖµÊDz»¿ÉÄܵġ£
´úÌæµÄ·½°¸ÊÇʹÓÃTIMESTAMPÀàÐÍ´úÌæDATETIMEÀàÐÍ¡£
CURRENT_TIMESTAMP £ºµ±ÎÒ¸üÐÂÕâÌõ¼Ç¼µÄʱºò£¬ÕâÌõ¼Ç¼µÄÕâ¸ö×ֶβ»»á¸Ä±ä
¡£
CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP £ºµ±ÎÒ¸üÐÂÕâÌõ¼Ç¼µÄʱºò£¬ÕâÌõ¼Ç¼µÄÕâ¸ö×ֶν«»á¸Ä±ä
¡£¼´Ê±¼ä±äΪÁ˸üÐÂʱºòµÄʱ¼ä¡££¨×¢ÒâÒ»¸öUPDATEÉèÖÃÒ»¸öÁÐΪËüÒѾ­ÓеÄÖµ£¬Õ⽫²»ÒýÆðTIMESTAMPÁб»¸üУ¬ÒòΪÈç¹ûÄãÉèÖÃÒ»¸öÁÐΪËüµ±Ç°µÄÖµ£¬MySQLΪÁËЧÂʶøºöÂÔ¸ü¸Ä¡££©Èç¹ûÓжà¸öTIMESTAMPÁУ¬Ö»ÓеÚÒ»¸ö×Ô¶¯¸üС£


Ïà¹ØÎĵµ£º

mysql ÂÒÂëÎÊÌâ¡£

show variables like 'character%';²é¿´×Ö·û±àÂë
--¸ü¸Ä×Ö·û¼¯
SET character_set_client = utf-8 ;
SET character_set_connection = utf-8 ;
SET character_set_database = utf-8 ;
SET character_set_results = utf-8 ;
SET character_set_server = utf-8 ;
SET collation_connection = utf8 ;
SET colla ......

mysql Ë÷Òý

1
Ë÷ÒýµÄÒâÒ壺
Óŵ㣺
Ë÷ÒýÓÃÀ´¿ìËÙµØÑ°ÕÒÄÇЩ¾ßÓÐÌØ¶¨ÖµµÄ¼Ç¼£¬Èç¹ûûÓÐË÷Òý£¬Ö´Ðвéѯʱ±ØÐë´ÓµÚÒ»¸ö¼Ç¼¿ªÊ¼É¨Ãè±íÖÐËùÓмǼ£¬±íÀïÃæµÄ¼Ç¼ÊýÁ¿Ô½¶à£¬Õâ¸ö²Ù×÷µÄ´ú¼Û¾ÍÔ½¸ß¡£
    
ȱµã£º
Ë÷ÒýÒªÕ¼ÓôÅÅ̿ռ䣻ÇÒÈκÎд²Ù×÷Éæ¼°µÄË÷Òý¸öÊý¶àµÄ»°»áÒýÆð½µËÙ£¬ÒòΪ
MySQL
²»½öÒª°Ñ¸Ä¶¯Êý¾ ......

mysqlÊý¾Ý¿â·¶Ê½Ïê½â

ÔÚÉè¼Æ¹ØÏµÊý¾Ý¿âʱÊÇÒª×ñÊØÒ»¶¨µÄ¹æÔòµÄ¡£ÓÈÆäÊÇÊý¾Ý¿âÉè¼Æ·¶Ê½ÏÖ¼òµ¥½éÉÜ1NF£¨µÚÒ»·¶Ê½£©£¬2NF£¨µÚ¶þ·¶Ê½£©£¬3NF£¨µÚÈý·¶Ê½£©ºÍBCNF£¬ÁíÓеÚËÄ·¶Ê½ºÍµÚÎ巶ʽÁôµ½ÒÔºóÔÙ½éÉÜ¡£ÔÚÄãÉè¼ÆÊý¾Ý¿â֮ʱ£¬ÈôÄÜ·ûºÏÕ⼸¸ö·¶Ê½£¬Äã¾ÍÊÇÊý¾Ý¿âÉè¼ÆµÄ¸ßÊÖ¡£
µÚÒ»·¶Ê½£¨1NF£©£ºÔÚ¹ØÏµÄ£Ê½RÖеÄÿһ¸ö¾ßÌå¹ØÏµrÖУ¬Èç¹ûÿ¸öÊôÐÔÖµ¶¼Ê ......

Mysql limitÓ÷¨

1.SELECT
 
*
 
from
 
table
 LIMIT
1
,
20
;  
//
 ¼ìË÷¼Ç¼ÐÐ
2-21
   µÚÒ»¸ö²ÎÊý£º²éѯÆðʼÐУ¨´Ó0¿ªÊ¼£©
   µÚ¶þ¸ö²ÎÊý£º²éѯ¼¸Ìõ¼Ç¼
2.
SELECT
 
*
 
from
 
table
 LIMIT
5
,
-
1

//
&nbs ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ