Mysql·分库分表

window环境下运行的，实际生产推荐在Linux上运行
使用前软件环境搭建
下载安装mysql:mysql-5.7.36-winx64
下载安装jdk-8u251-windows-x64
下载安装Mycat-server-1.3.0.3-release-20150527095523-win

在mysql中新建数据库用以表分库分表

create database yy01;
create database yy02;
create database yy03;

select 'yy01',a.* from yy01.item a union all 
select 'yy02',a.* from yy02.item a union all 
select 'yy03',a.* from yy03.item a  ;

explain select * from item ;

mycat解压后配置文件参数

server.xml 主要配置mycat服务的参数，比如端口号，myact用户名和密码使用的逻辑数据库等

DOCTYPE mycat:server SYSTEM "server.dtd">
<mycat:server xmlns:mycat="http://org.opencloudb/">
	<system>
	<property name="defaultSqlParser">druidparserproperty>

	system>
	<user name="test">
		<property name="password">testproperty>
		<property name="schemas">TESTDBproperty>	
	user>

	<user name="user">
		<property name="password">userproperty>
		<property name="schemas">TESTDBproperty>
		<property name="readOnly">trueproperty>
	user>
mycat:server>

rule.xml 主要配置路由策略，主要有分片的片键，拆分的策略（取模还是按区间划分等）

DOCTYPE mycat:rule SYSTEM "rule.dtd">
<mycat:rule xmlns:mycat="http://org.opencloudb/">

<tableRule name="role1">
    <rule>
        <columns>idcolumns>
        <algorithm>mod-longalgorithm>
    rule>
tableRule>

<tableRule name="rule1">
<rule>
<columns>idcolumns>
<algorithm>func1algorithm>
rule>
tableRule>
<tableRule name="rule2">
<rule>
<columns>user_idcolumns>
<algorithm>func1algorithm>
rule>
tableRule>
<tableRule name="sharding-by-intfile">
<rule>
<columns>sharding_idcolumns>
<algorithm>hash-intalgorithm>
rule>
tableRule>
<tableRule name="auto-sharding-long">
<rule>
<columns>idcolumns>
<algorithm>rang-longalgorithm>
rule>
tableRule>
<tableRule name="mod-long">
<rule>
<columns>idcolumns>
<algorithm>mod-longalgorithm>
rule>
tableRule>
<tableRule name="sharding-by-murmur">
<rule>
<columns>idcolumns>
<algorithm>murmuralgorithm>
rule>
tableRule>
   
   <function name="murmur" class="org.opencloudb.route.function.PartitionByMurmurHash">
      <property name="seed">0property>
      <property name="count">2property>
      <property name="virtualBucketTimes">160property>
  function>
  <function name="hash-int" class="org.opencloudb.route.function.PartitionByFileMap">
    <property name="mapFile">partition-hash-int.txtproperty>
  function>
   <function name="rang-long" class="org.opencloudb.route.function.AutoPartitionByLong">
    <property name="mapFile">autopartition-long.txtproperty>
  function>
  <function name="mod-long" class="org.opencloudb.route.function.PartitionByMod">
   
    <property name="count">3property>
  function>
  
  <function name="func1" class="org.opencloudb.route.function.PartitionByLong">
    <property name="partitionCount">8property>
    <property name="partitionLength">128property>
  function>
mycat:rule>

schema.xml 文件主要配置数据库的信息，例如逻辑数据库名称，物理上真实的数据源以及表和数据源之间的对应关系和路由策略等。

DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://org.opencloudb/">

	<schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100">

        
        <table name="users" primaryKey="id"  dataNode="dn1,dn2,dn3" />  
        
        <table name="item" primaryKey="id" dataNode="dn1,dn2,dn3" rule="role1" /> 
        <table name="users2" primaryKey="id" dataNode="dn1,dn2,dn3" rule="role1" />
        <table name="orders" primaryKey="id" dataNode="dn1,dn2,dn3" rule="role1" />
	schema>

	<dataNode name="dn1" dataHost="localhost1" database="yy01" />
	<dataNode name="dn2" dataHost="localhost1" database="yy02" />
	<dataNode name="dn3" dataHost="localhost1" database="yy03" />
	
	<dataHost name="localhost1" maxCon="1000" minCon="10" balance="0"
		writeType="0" dbType="mysql" dbDriver="native">
		<heartbeat>select user()heartbeat>
		
		<writeHost host="hostM1" url="localhost:3306" user="root"
			password="123456">
			
			
		writeHost>
		
	dataHost>
	 
mycat:schema>

启动mycat

出现此画面说明启动成功

验证结果
在命令行访问mycat逻辑数据库，采用如下的命令：
mysql -utest -ptest -h127.0.0.1 -P8066 -DTESTDB
现在通过数据库查询数据库和表，发现只有逻辑数据库TESTDB而不是yy01, yy02, yy03；而且表也是统一显示的，而不是分布在不同的实际数据库中。参考图片如下：

在TESTDB库中创建item表用以测试
drop table if exists item ; 
CREATE TABLE item (  
    id INT NOT NULL AUTO_INCREMENT,  
    d_name varchar(100) ,  
    d_date varchar(100)  default '0000-00-00 00:00:00',  
    PRIMARY KEY (id)  
)AUTO_INCREMENT= 1 ENGINE=InnoDB DEFAULT CHARSET=utf8;

insert into item (id,d_name,d_date) values(01,'秦时明月',now());
insert into item (id,d_name,d_date) values(02,'秦时明月',now());
insert into item (id,d_name,d_date) values(03,'秦时明月',now());
insert into item (id,d_name,d_date) values(04,'秦时明月',now());
insert into item (id,d_name,d_date) values(05,'秦时明月',now());
insert into item (id,d_name,d_date) values(06,'秦时明月',now());
insert into item (id,d_name,d_date) values(07,'秦时明月',now());
insert into item (id,d_name,d_date) values(08,'秦时明月',now());
insert into item (id,d_name,d_date) values(09,'秦时明月',now());
insert into item (id,d_name,d_date) values(10,'秦时明月',now());
insert into item (id,d_name,d_date) values(11,'秦时明月',now());
insert into item (id,d_name,d_date) values(12,'秦时明月',now());
insert into item (id,d_name,d_date) values(13,'秦时明月',now());

select 'yy01',a.* from yy01.item a union all 
select 'yy02',a.* from yy02.item a union all 
select 'yy03',a.* from yy03.item a  ;

explain select * from item ;

如下图所示，mycat配置分库分表成功

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