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

Mysql ¸´ÖÆ±í¼°½á¹¹

Ò»¡¢CREATE TABLE ·½·¨
Õû±í¸´ÖÆ # create table бí select * from ¾É±í;
½á¹¹¸´ÖÆ # create table бí select * from ¾É±í where 1<>1;
¶þ¡¢INSERT INTO ·½·¨
µÃµ½½¨±íÓï¾ä # show create table ¾É±í;
н¨±í
¸´ÖÆÊý¾Ýµ½Ð±í INSERT INTO new_table(col1,col2,...) (SELECT col1,col2,... from old_table);


Ïà¹ØÎĵµ£º

¸÷λÀ´¿´¿´£ºMySQL´´Ê¼ÈË·¢ÓʼþѰÇóÖйú°ïÖú!

ÔÚJavaEye¿´µ½ÒÔϵÄÄÚÈÝ£¬Á´½ÓµØÖ·£ºhttp://www.javaeye.com/news/13062-mysql£¬Ï£Íûϲ°®MySqlµÄÅóÓÑÃÇÒ»ÆðÖ§³Ö¡£
ÇëÔ¸Ê鵨ַ£ºhttp://helpmysql.org/cn/petition
Ç×°®µÄÕü¾ÈMySQLµÄÖйúÇ©ÃûÖ§³ÖÕß:
    Å·ÃË¿ÉÄÜÎÞ·¨Õü¾ÈMySQL, ÖйúºÍ¶íÂÞ˹¿ÉÄÜÊÇÕü¾ÈMySQLµÄÏ£ÍûÖ®ËùÔÚ¡£ÖйúÓµÓÐÇ¿´ó¡¢¶ÀÁ¢ÒÔ¼°×ÔÐŵ ......

mysqlºÍoracle·ÖÒ³×¢Òâµã

ÕâÀïÊ×ÏÈ˵ÏÂoracle·ÖÒ³²»Ïñmysql·ÖÒ³ÄÇô¼òµ¥Ö±½Ólimit ¾Í¿ÉÒÔÁË.
mysql£ºsql ="select * from talbe limit 0,10";
µÚÒ»¸öÊý±íʾϱ꣬¾ÍÊÇ´ÓµÚ¼¸ÌõÊý¾Ý¿ªÊ¼£¬
µÚ¶þ¸öÊý±íʾÿҳÏÔʾ¶àÉÙÌõÊý¾Ý£¬¿ÉÒÔ˵Êǵ±ÄãÈ·¶¨Ã¿Ò³ÏÔʾ¶àÉÙÐÐʱºò£¬Ëü¾ÍÊÇÒ»¸ö¹Ì¶¨µÄÊý¡£
ÕâÀïÐèҪעÒâµÄÊÇ£¬mysqlµÄ·ÃÎÊϱêÊÇ´Ó0¿ªÊ¼µÄ¡£Õ ......

mysql ÖеÄ×Ö·û´®Á¬½Ó CONCAT(str1,str2,...)

·µ»ØÀ´×ÔÓÚ²ÎÊýÁ¬½áµÄ×Ö·û´®¡£Èç¹ûÈκβÎÊýÊÇNULL£¬·µ»ØNULL¡£¿ÉÒÔÓг¬¹ý2¸öµÄ²ÎÊý¡£Ò»¸öÊý×Ö²ÎÊý±»±ä»»ÎªµÈ¼ÛµÄ×Ö·û´®ÐÎʽ¡£
mysql> select CONCAT('My', 'S', 'QL');
-> 'MySQL'
mysql> select CONCAT('My', NULL, 'QL');
-> NULL
mysql> select CONCAT(14.3);
-> '14.3'
È磺update test set ......

MYSQLÊý¾Ý¿âµ¼Èë¡¢µ¼³ö

1.mysqlµ¼³öÊý¾Ý¿âÃüÁî
C:\Program Files\MySQL\MySQL Server 5.0\bin>mysqldump -u Óû§Ãû -p Êý¾Ý¿âÃû (±íÃû) > c:\\ÎļþÃû.sql
2.mysqlµ¼ÈëÊý¾Ý¿âÃüÁî
£¨1£©½â¾öÖÐÎÄÂÒÂëÎÊÌ⣺ִÐÐÈçÏÂÃüÁîÔÙµ¼È룺set names utf8
£¨2£©µÇ¼mysql£¬Ö´ÐÐÈçÏÂÃüÁ
mysql> source c:\\ÎļþÃû.sql;
3½â¾öÖÐÎÄÂÒÂëÎÊÌ⣺ִР......

MySQLСÊýλȡÕû

//µÃ·Ö¼ÆËãËÄÉáÎåÈë
SELECT ROUND((SUM(getfeng)/SUM(totalfeng))*100) as feng from answerdata WHERE uid='151' AND targetid IS NOT NULL
1.ceil £¨£© /ceiling£¨£© ÏòÉÏÈ¡Õû
   Àý£º ceil£¨1.2£© = 2
2.floor £¨£© ÏòÏÂÈ¡Õû
    Àý£º floor£¨1.2£© = 1
3.round£¨£© ËÄÉáÎåÈë
 &n ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ