<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0">
  <channel>
    <title>学习笔记 - mysql</title>
    <link>https://22938.cn/forum.php?mod=forumdisplay&amp;fid=41</link>
    <description>Latest 20 threads of mysql</description>
    <copyright>Copyright(C) 学习笔记</copyright>
    <generator>Discuz! Board by Comsenz Inc.</generator>
    <lastBuildDate>Mon, 27 Apr 2026 14:44:18 +0000</lastBuildDate>
    <ttl>60</ttl>
    <image>
      <url>https://22938.cn/static/image/common/logo_88_31.gif</url>
      <title>学习笔记</title>
      <link>https://22938.cn/</link>
    </image>
    <item>
      <title>character-set-client-handshake=false</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=69</link>
      <description><![CDATA[[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld un]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Sun, 14 May 2023 10:02:35 +0000</pubDate>
    </item>
    <item>
      <title>load data local infile加载文本文件到表</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=66</link>
      <description><![CDATA[load data local infile \'file_path\' into table tb_name line terminated by \'\\r\\n\';
文本文件每行一个记录，字段间用TAB隔开，\'\\r\\n\'为导入windows format txtfile时需要]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Mon, 01 May 2023 09:48:36 +0000</pubDate>
    </item>
    <item>
      <title>mysql运算符和流程控制</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=65</link>
      <description><![CDATA[1、算术运算符
+、-、*、/、%、DIV、MOD，DIV和MOD只有2个参数，进行除尘和求余时，后面参数为0时，结果为NULL。


2、比较运算符
=、&gt;、=、]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Mon, 01 May 2023 07:19:38 +0000</pubDate>
    </item>
    <item>
      <title>复制表create table删除表drop table</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=64</link>
      <description><![CDATA[create table  tb_name2 like tb_name1;
使用该语法复制数据表时，将创建一个与源数据表相同结构的新表，该数据表的列名、数据类型空指定、索引都将被复制，但表的内容是不会复制的，即新创建的表是一张空表。


create table  tb_name2 as select *from tb_name1;
复制 ...]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Mon, 01 May 2023 06:44:01 +0000</pubDate>
    </item>
    <item>
      <title>查看表结构show columns和describe</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=63</link>
      <description><![CDATA[show [full] columns from tb_name [from db_name];


desc tb_name;


desc tb_name col_name;]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Mon, 01 May 2023 03:27:29 +0000</pubDate>
    </item>
    <item>
      <title>alter table 更改表</title>
      <link>https://22938.cn/forum.php?mod=viewthread&amp;tid=62</link>
      <description><![CDATA[alter table tb_name add [column] col_definition [first | after some_column];添加新字段

alter table tb_name add index  (index_col_name,...);
添加索引

alter table tb_name drop index index_name;
删除索引

alter table tb_name add primary key (index_col ...]]></description>
      <category>mysql</category>
      <author>admin</author>
      <pubDate>Mon, 01 May 2023 03:24:23 +0000</pubDate>
    </item>
  </channel>
</rss>