根据数据库的ER模型进行分库，即进行多表关联分库管理

schema.xml

<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
        <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100">
                <!--此处表示父表与子表的相互关联-->
                <table name="data" primaryKey="id" dataNode="dn$1-3" rule="my-mod-long">
                        <childTable name="data_details" joinKey="id" primaryKey="ddid" parentKey="id"/>
                </table>
        </schema>
        <dataNode name="dn1" dataHost="localhost1" database="db1" />
        <dataNode name="dn2" dataHost="localhost2" database="db2" />
        <dataNode name="dn3" dataHost="localhost3" database="db3" />
        <dataHost name="localhost1" maxCon="1000" minCon="10" balance="2"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="host1" url="192.168.122.166:3306" user="root" password="123456"/>
        </dataHost>
        <dataHost name="localhost2" maxCon="1000" minCon="10" balance="2"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="host2" url="192.168.122.199:3306" user="root" password="123456"/>
        </dataHost>
        <dataHost name="localhost3" maxCon="1000" minCon="10" balance="2"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>
                <writeHost host="host3" url="192.168.122.198:3306" user="root" password="123456"/>
        </dataHost>
</mycat:schema>