美文网首页mysqlHadoop
SQL简记(一)

SQL简记(一)

作者: 和心数据 | 来源:发表于2017-02-22 19:07 被阅读28次

    1 Mysql相关

    1 .1 启动/停止命令

    win: net start/stop mysql
    linux: service mysqld start/stop

    1.2 用户

    创建用户:create user szh@localhost identified by "123456";
    授权:grant all on . to 'szh'@'localhost' identified by '123456'; 刷新:flush privileges;
    设置密码:set password for szh@localhost=password("123456");
    解除授权:revoke all on . from local@localhost;
    更多请查看这里

    1.3 字符集

    1)查看字符集:show variables like '%char%';
    2)修改字符集(配置文件)
    复制my-default.ini为my.ini,按照下面的进行修改和补全,保存后进行重启

    # For advice on how to change settings please see
    # http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
    # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
    # *** default location during install, and will be replaced if you
    # *** upgrade to a newer version of MySQL.
    
    [mysqld]
    character-set-server=utf8
    
    # Remove leading # and set to the amount of RAM for the most important data
    # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
    # innodb_buffer_pool_size = 128M
    
    # Remove leading # to turn on a very important data integrity option: logging
    # changes to the binary log between backups.
    # log_bin
    
    # These are commonly set, remove the # and set as required.
    # basedir = D:\SoftWare\JAVA\JavaWeb\mysql-5.7.13-win32\mysql-5.7.13-win32
    # datadir = D:\SoftWare\JAVA\JavaWeb\mysql-5.7.13-win32\mysql-5.7.13-win32\data
    # port = .....
    # server_id = .....
    [client]
    loose-default-character-set=utf8
    default-character-set=utf8
    [mysql]
    default-character-set=utf8
    
    # Remove leading # to set options mainly useful for reporting servers.
    # The server defaults are faster for transactions and fast SELECTs.
    # Adjust sizes as needed, experiment to find the optimal values.
    # join_buffer_size = 128M
    # sort_buffer_size = 2M
    # read_rnd_buffer_size = 2M 
    
    # sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
    

    3)修改数据库的字符集
    alter database db_name character set utf8;
    4)修改表格的字符集
    alter table tb_name character set utf8 collate utf_general_ci;

    2 SQL相关

    2.1 查询

    查询

    2.2 过滤:where后面的条件

    过滤

    待续...

    相关文章

      网友评论

        本文标题:SQL简记(一)

        本文链接:https://www.haomeiwen.com/subject/jcimwttx.html