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select * for updateËø±íµÄÎÊÌâ
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¾Ù¸öÀý×Ó:
¼ÙÉèÓиö±íµ¥products £¬ÀïÃæÓÐid¸úname¶þ¸öÀ¸Î»£¬idÊÇÖ÷¼ü¡£
Àý1: (Ã÷È·Ö¸¶¨Ö÷¼ü£¬²¢ÇÒÓд˱Ê×ÊÁÏ£¬row lock)
SELECT * from products WHERE id='3' FOR UPDATE;
Àý2: (Ã÷È·Ö¸¶¨Ö÷¼ü£¬Èô²éÎ޴˱Ê×ÊÁÏ£¬ÎÞlock)
SELECT * from products WHERE id='-1' FOR UPDATE;
Àý2: (ÎÞÖ÷¼ü£¬table lock)
SELECT * from products WHERE name='Mouse' FOR UPDATE;
Àý3: (Ö÷¼ü²»Ã÷È·£¬table lock)
SELECT * from products WHERE id<>'3' FOR UPDATE;
Àý4: (Ö÷¼ü²»Ã÷È·£¬table lock)
SELECT * from products WHERE id LIKE '3' FOR UPDATE;
×¢1: FOR UPDATE½öÊÊÓÃÓÚInnoDB£¬ÇÒ±ØÐëÔÚ½»Ò×Çø¿é(BEGIN/COMMIT)ÖвÅÄÜÉúЧ¡£
×¢2: Òª²âÊÔ
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mysql״̬ status

http://blog.163.com/mysqldba@126/blog/static/1315356342009931103834396/
×î½ü¿´ÁË¿´mysqlµÄ״̬±äÁ¿£¬¸Ð¾õºÃ¶à¸úÒÔǰ×Ô¼ºÏëÏóµÄ²»Ò»Ñù¡£ÎªÁËÒÔºóÄܼ°Ê±·¢ÏÖ×Ô¼ºµÄ´íÎó,¾ÍÏȼÇÏÂÀ´;
http://dev.mysql.com/doc/refman/5.1/en/server-status-variables.html
mysql> show status;
Com_xxx
Óï¾ä¼ÆÊý±äÁ¿±íʾÿ¸öxxx ......

mysqlº¯Êý


ÓÃÔÚSELECTºÍWHERE×Ó¾äµÄº¯Êý
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1 ·Ö×麯Êý
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£¨+ - * /£©
Ò»°ãµÄË ......

windowsµÄ64λƽ̨railsÁ¬½ÓmysqlµÄ·½·¨


°²×°mysql
gem install mysql
ʹÓÃmysql£¬È磬rake db:migrate
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E:\study\ruby\rails_space>rake db:migrate
(in E:/study/ruby/rails_space)
!!! The bundled mysql.rb driver has been removed from Rails 2.2. Please install the mysql gem and try again: gem install mysql.
rake aborted!
193: ......

JDBCÁ¬½ÓMySQLÊý¾Ý¿âʵÏÖÔöɾ²é¸Ä

package com.qll.operate;
import java.sql.*;
public class OperateUser {
 String driver = "com.mysql.jdbc.Driver";
 String url = "jdbc:mysql://localhost:3306/test";
 String name = "root";
 String password = "123456";
 static Connection conn = null;
 Statement st = ......

mysql errno: 150 ´íÎó Íâ¼ü

ERROR 1005 (HY000): Can't create table '  ****.frm' (errno: 150)
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