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借助MyCat来实现MySQL的分库分表落地，没有实现过的，或者没了解过的可以看看
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前言

在之前写过一篇关于mysql分库分表的文章，那篇文章只是给大家提供了一个思路，但是回复下面有很多说是细节问题没有提到。所以咔咔就在出了这篇文章。

本文只是针对其中的一个细节而已，比如如何落地MySQL的分库分表，本文使用数据库中间件MyCat来实现。

其中还有最多的回复是分库分表后的分页查询如何操作，这个问题也会在后文继续写到。

关于MySQL分库分表这个真正落地使用中间还有很多的问题，咔咔尽量把解决方案都提供给大家，如你有更好的实现方案，评论区见哈！

本文使用环境

MySQL8.0
Centos7.3

一、MyCat安装

避免提示广告问题，自己去打开MyCat的官方地址去复制下载地址，这里咔咔就不提供了。

咔咔使用的虚拟机是centos7.3，需要环境的jdk已经有了，就不在写教程了。如没有的话，百度搜搜就可以了哈！

下图就是安装成功的安装包在这里插入图片描述进行解压：tar -zxvf Mycat-server-1.6.7.1-release-20200209222254-linux.tar.gz，解压成功后会在目录下存在一个mycat目录。

二、创建一个新的MySQL用户

需要创建一个新的MySQL用户用来连接Mycat

以下就是创建用户的流程

<span style="display: block; background: url(https://my-wechat.mdnice.com/point.png); height: 30px; width: 100%; background-size: 40px; background-repeat: no-repeat; background-color: #272822; margin-bottom: -7px; border-radius: 5px; background-position: 10px 10px;"></span><code class="hljs" style="overflow-x: auto; padding: 16px; color: #ddd; display: -webkit-box; font-family: Operator Mono, Consolas, Monaco, Menlo, monospace; font-size: 12px; -webkit-overflow-scrolling: touch; letter-spacing: 0px; padding-top: 15px; background: #272822; border-radius: 5px;">// 创建mycat用户<br/>CREATE USER <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;mycat&#39;</span>@<span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;%&#39;</span> IDENTIFIED BY <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;mycat&#39;</span>;<br/>// 修改密码<br/>ALTER USER <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;mycat&#39;</span>@<span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;%&#39;</span> IDENTIFIED WITH mysql_native_password BY ’Fang,1996<span class="hljs-string" style="color: #a6e22e; line-height: 26px;">&#39;; <br/>// 刷新权限<br/>FLUSH PRIVILEGES;<br/></span></code>

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三、配置MyCat

配置项一：server.xml

此处使用上边创建的新的MySQL用户mycat，可以管理的逻辑库为mycat_order，对应schema.xml中的

框出的来的解读一下

第一行：name值后边是上边创建的MySQL用户第二行：是mycat用户的密码第三行：是数据库

在这里插入图片描述配置项二：schema.xml

这个文件主要修改连接其他数据库的俩个节点

使用规则是mod-long这个需要注意一下子

在这块的配置咔咔卡了很久，下面这个是咔咔已经配置好的在这里插入图片描述

配置项三：rule.xml

这里是order_id使用mod-long规则在这里插入图片描述这个修改就是你有几个节点就写多少即可

三、数据库信息准备

在俩台服务器114.55.103.25和192.168.253.129创建数据库kaka和kaka

分别创建t_order和t_order_detail俩张表

表结构如下

<span style="display: block; background: url(https://my-wechat.mdnice.com/point.png); height: 30px; width: 100%; background-size: 40px; background-repeat: no-repeat; background-color: #272822; margin-bottom: -7px; border-radius: 5px; background-position: 10px 10px;"></span><code class="hljs" style="overflow-x: auto; padding: 16px; color: #ddd; display: -webkit-box; font-family: Operator Mono, Consolas, Monaco, Menlo, monospace; font-size: 12px; -webkit-overflow-scrolling: touch; letter-spacing: 0px; padding-top: 15px; background: #272822; border-radius: 5px;"><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">CREATE</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">TABLE</span> <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`t_order_detail`</span> (<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`od_id`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">int</span>(<span class="hljs-number" style="line-height: 26px;">11</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">NOT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`order_id`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">int</span>(<span class="hljs-number" style="line-height: 26px;">11</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`goods_id`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">int</span>(<span class="hljs-number" style="line-height: 26px;">11</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`unit_price`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">float</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`qty`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">int</span>(<span class="hljs-number" style="line-height: 26px;">11</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  PRIMARY <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">KEY</span> (<span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`od_id`</span>)<br/>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">ENGINE</span>=<span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">InnoDB</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">CHARSET</span>=utf8;<br/><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">CREATE</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">TABLE</span> <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`t_order`</span> (<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`order_id`</span> bagint(<span class="hljs-number" style="line-height: 26px;">20</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">NOT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`user_id`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">int</span>(<span class="hljs-number" style="line-height: 26px;">11</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`pay_mode`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">tinyint</span>(<span class="hljs-number" style="line-height: 26px;">4</span>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`amount`</span> <span class="hljs-built_in" style="color: #a6e22e; line-height: 26px;">float</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  <span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`order_date`</span> datetime <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-literal" style="color: #f92672; font-weight: bold; line-height: 26px;">NULL</span>,<br/>  PRIMARY <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">KEY</span> (<span class="hljs-string" style="color: #a6e22e; line-height: 26px;">`order_id`</span>)<br/>) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">ENGINE</span>=<span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">InnoDB</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">DEFAULT</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">CHARSET</span>=utf8;<br/></code>

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四、测试连接并插入数据，查看数据分布状态

连接：mysql -umycat -p -P8066 -h192.168.253.129 --default-auth=mysql_native_password

连接成功就可以看到我们的逻辑库在这里插入图片描述然后添加三个数据

<span style="display: block; background: url(https://my-wechat.mdnice.com/point.png); height: 30px; width: 100%; background-size: 40px; background-repeat: no-repeat; background-color: #272822; margin-bottom: -7px; border-radius: 5px; background-position: 10px 10px;"></span><code class="hljs" style="overflow-x: auto; padding: 16px; color: #ddd; display: -webkit-box; font-family: Operator Mono, Consolas, Monaco, Menlo, monospace; font-size: 12px; -webkit-overflow-scrolling: touch; letter-spacing: 0px; padding-top: 15px; background: #272822; border-radius: 5px;"><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">insert</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">into</span> t_order (order_id,user_id,pay_mode,amount) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">values</span> (<span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">next</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">value</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">for</span> MYCATSEQ_ORDER,<span class="hljs-number" style="line-height: 26px;">103</span>,<span class="hljs-number" style="line-height: 26px;">1</span><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">Query</span> OK, <span class="hljs-number" style="line-height: 26px;">1</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">row</span> affected (<span class="hljs-number" style="line-height: 26px;">0.01</span> sec)<br/><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">insert</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">into</span> t_order (order_id,user_id,pay_mode,amount) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">values</span> (<span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">next</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">value</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">for</span> MYCATSEQ_ORDER,<span class="hljs-number" style="line-height: 26px;">103</span>,<span class="hljs-number" style="line-height: 26px;">1</span><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">Query</span> OK, <span class="hljs-number" style="line-height: 26px;">1</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">row</span> affected (<span class="hljs-number" style="line-height: 26px;">0.01</span> sec)<br/><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">insert</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">into</span> t_order (order_id,user_id,pay_mode,amount) <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">values</span> (<span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">next</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">value</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">for</span> MYCATSEQ_ORDER,<span class="hljs-number" style="line-height: 26px;">103</span>,<span class="hljs-number" style="line-height: 26px;">1</span><br/><span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">Query</span> OK, <span class="hljs-number" style="line-height: 26px;">1</span> <span class="hljs-keyword" style="color: #f92672; font-weight: bold; line-height: 26px;">row</span> affected (<span class="hljs-number" style="line-height: 26px;">0.01</span> sec)<br/></code>

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这个时候我们查看一下逻辑库的t_order数据，这里的order_id本应该是从1000开始的，之前咔咔做测试使用了一些。在这里插入图片描述这时我们在来看192.168.253.129和114.55.103.25这俩台数据库的数据分布