mysql初次探索

记得上学的时候，“研究”过一次mysql，找了篇文章，在课堂上念了。至今已经10余年，居然没再碰过数据库，自以为做嵌入式不用数据库，回头一看，却已经out许久...

    上网下到最新的mysql5.5，从头开始，以下全是按照官方指南执行的简化。

    1、准备：

    没cmake的装cmake，没make的装make，没perl的装perl，没gcc的...！

    2、编译：

    cd $MYSQL_SRC_DIR

    cmake .(这儿有个点儿)

    make install (多核的别忘了-j n，真的很快)

    默认安装到/usr/local/mysql

    cd /usr/local/mysql

    3、配置：

    我配置时是用的root用户，开发么，没管那么多。

    scripts/mysql_install_db --user=mysql (root用户必须加上user选项)

    脚本会在当前目录下建立data目录：

    chown -R mysql data (修改一下所有者为mysql)

    4、执行：

    bin/mysqld_safe --user=mysql &

    有问题如下：

 120630 22:50:11 mysqld_safe Logging to '/var/log/mysqld.log'.
 120630 22:50:11 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
 120630 22:50:12 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended

    看一下/var/log/mysqld.log

 120630 23:07:15 [ERROR] /usr/local/mysql/bin/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 2)
 120630 23:07:15 [ERROR] Can't start server: can't create PID file: No such file or directory

    没那个目录，自己建一个，再加上权限，重新执行，提示：

 120630 23:18:53 mysqld_safe Logging to '/var/log/mysqld.log'.
 120630 23:18:53 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

    应该是成功了。

    5、测试：

    bin/mysqladmin version，提示错误：

 /usr/local/mysql/bin/mysqladmin: connect to server at 'localhost' failed
 error: 'Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)'
 Check that mysqld is running and that the socket: '/tmp/mysql.sock' exists!

    找mysql.sock这货没找到，看一下/etc/my.cnf (这是mysqld自己创建的，不愿意用可以到support-files下自己再找一个，反正都不是自己写的，以后再研究吧)：

 socket=/var/lib/mysql/mysql.sock

    socket建立在/var下，那就ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock，什么都不用改了

    再执行bin/mysqladmin version，提示：

 /usr/local/mysql/bin/mysqladmin  Ver 8.42 Distrib 5.5.24, for Linux on i686
 Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

 Oracle is a registered trademark of Oracle Corporation and/or its
 affiliates. Other names may be trademarks of their respective
 owners.

 Server version          5.5.24
 Protocol version        10
 Connection              Localhost via UNIX socket
 UNIX socket             /tmp/mysql.sock
 Uptime:                 37 min 53 sec

 Threads: 1  Questions: 20  Slow queries: 0  Opens: 33  Flush tables: 1  Open tables: 26  Queries per second avg: 0.008

    OK，其它的测试照着文档一点点的测就好了。