Sharding

Not Use Spring

Introduce Maven Dependency

<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>sharding-jdbc-core</artifactId>
    <version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Java

Database sharding and table sharding of Sharding-JDBC configure descriptions according to rules. The following example is two databases plus two tables configurations, whose databases take module and split according to order_id, tables take module and split according to order_id.

    // Configure actual data sources
    Map<String, DataSource> dataSourceMap = new HashMap<>();
    
    // Configure first data source
    BasicDataSource dataSource1 = new BasicDataSource();
    dataSource1.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource1.setUrl("jdbc:mysql://localhost:3306/ds0");
    dataSource1.setUsername("root");
    dataSource1.setPassword("");
    dataSourceMap.put("ds0", dataSource1);
    
    // Configure second data source
    BasicDataSource dataSource2 = new BasicDataSource();
    dataSource2.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource2.setUrl("jdbc:mysql://localhost:3306/ds1");
    dataSource2.setUsername("root");
    dataSource2.setPassword("");
    dataSourceMap.put("ds1", dataSource2);
    
    // Configure table rule for Order
    TableRuleConfiguration orderTableRuleConfig = new TableRuleConfiguration();
    orderTableRuleConfig.setLogicTable("t_order");
    orderTableRuleConfig.setActualDataNodes("ds${0..1}.t_order${0..1}");
    
    // Configure strategies for database + table sharding 
    orderTableRuleConfig.setDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("user_id", "ds${user_id % 2}"));
    orderTableRuleConfig.setTableShardingStrategyConfig(new InlineShardingStrategyConfiguration("order_id", "t_order${order_id % 2}"));
    
    // Configure sharding rule
    ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
    shardingRuleConfig.getTableRuleConfigs().add(orderTableRuleConfig);
    
    // Configure table rule for order_item
    // ...
    
    // Get data source
    DataSource dataSource = ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig, new ConcurrentHashMap(), new Properties());

Rule Configuration Based on Yaml

Or use Yaml to configure, similar to above configurations:

dataSources:
  ds0: !!org.apache.commons.dbcp.BasicDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ds0
    username: root
    password: 
  ds1: !!org.apache.commons.dbcp.BasicDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ds1
    username: root
    password: 

tables:
  t_order: 
    actualDataNodes: ds${0..1}.t_order${0..1}
    databaseStrategy: 
      inline:
        shardingColumn: user_id
        algorithmInlineExpression: ds${user_id % 2}
    tableStrategy: 
      inline:
        shardingColumn: order_id
        algorithmInlineExpression: t_order${order_id % 2}
  t_order_item: 
    actualDataNodes: ds${0..1}.t_order_item${0..1}
    databaseStrategy: 
      inline:
        shardingColumn: user_id
        algorithmInlineExpression: ds${user_id % 2}
    tableStrategy: 
      inline:
        shardingColumn: order_id
        algorithmInlineExpression: t_order_item${order_id % 2}
    DataSource dataSource = ShardingDataSourceFactory.createDataSource(yamlFile);

Use Native JDBC

Configure objects with ShardingDataSourceFactory or YamlShardingDataSourceFactory to get ShardingDataSource, which is realized by standard JDBC DataSource interface. Or choose native JDBC to develop through DataSource; or use JPA, MyBatis and other ORM tools. Take native JDBC for example:

DataSource dataSource = ShardingDataSourceFactory.createDataSource(yamlFile);
String sql = "SELECT i.* FROM t_order o JOIN t_order_item i ON o.order_id=i.order_id WHERE o.user_id=? AND o.order_id=?";
try (
        Connection conn = dataSource.getConnection();
        PreparedStatement preparedStatement = conn.prepareStatement(sql)) {
    preparedStatement.setInt(1, 10);
    preparedStatement.setInt(2, 1001);
    try (ResultSet rs = preparedStatement.executeQuery()) {
        while(rs.next()) {
            System.out.println(rs.getInt(1));
            System.out.println(rs.getInt(2));
        }
    }
}

Using Spring

Introduce Maven Dependency

<!-- for spring boot -->
<dependency>
    <groupId>io.shardingsphere</groupId>
    <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
    <version>${sharding-sphere.version}</version>
</dependency>

<!-- for spring namespace -->
<dependency>
    <groupId>io.shardingsphere</groupId>
    <artifactId>sharding-jdbc-spring-namespace</artifactId>
    <version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Spring Boot

sharding.jdbc.datasource.names=ds0,ds1

sharding.jdbc.datasource.ds0.type=org.apache.commons.dbcp2.BasicDataSource
sharding.jdbc.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds0.url=jdbc:mysql://localhost:3306/ds0
sharding.jdbc.datasource.ds0.username=root
sharding.jdbc.datasource.ds0.password=

sharding.jdbc.datasource.ds1.type=org.apache.commons.dbcp2.BasicDataSource
sharding.jdbc.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds1.url=jdbc:mysql://localhost:3306/ds1
sharding.jdbc.datasource.ds1.username=root
sharding.jdbc.datasource.ds1.password=

sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=user_id
sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=ds$->{user_id % 2}

sharding.jdbc.config.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{0..1}
sharding.jdbc.config.sharding.tables.t_order.table-strategy.inline.sharding-column=order_id
sharding.jdbc.config.sharding.tables.t_order.table-strategy.inline.algorithm-expression=t_order$->{order_id % 2}

sharding.jdbc.config.sharding.tables.t_order_item.actual-data-nodes=ds$->{0..1}.t_order_item$->{0..1}
sharding.jdbc.config.sharding.tables.t_order_item.table-strategy.inline.sharding-column=order_id
sharding.jdbc.config.sharding.tables.t_order_item.table-strategy.inline.algorithm-expression=t_order_item$->{order_id % 2}

Rule Configuration Based on Spring Name Space

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:sharding="http://shardingsphere.io/schema/shardingsphere/sharding" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://shardingsphere.io/schema/shardingsphere/sharding 
                        http://shardingsphere.io/schema/shardingsphere/sharding/sharding.xsd 
                        ">
    <bean id="ds0" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/ds0" />
        <property name="username" value="root" />
        <property name="password" value="" />
    </bean>
    <bean id="ds1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/ds1" />
        <property name="username" value="root" />
        <property name="password" value="" />
    </bean>
    
    <sharding:inline-strategy id="databaseStrategy" sharding-column="user_id" algorithm-expression="ds$->{user_id % 2}" />
    <sharding:inline-strategy id="orderTableStrategy" sharding-column="order_id" algorithm-expression="t_order$->{order_id % 2}" />
    <sharding:inline-strategy id="orderItemTableStrategy" sharding-column="order_id" algorithm-expression="t_order_item$->{order_id % 2}" />
    
    <sharding:data-source id="shardingDataSource">
        <sharding:sharding-rule data-source-names="ds0,ds1">
            <sharding:table-rules>
                <sharding:table-rule logic-table="t_order" actual-data-nodes="ds$->{0..1}.t_order$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderTableStrategy" />
                <sharding:table-rule logic-table="t_order_item" actual-data-nodes="ds$->{0..1}.t_order_item$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderItemTableStrategy" />
            </sharding:table-rules>
        </sharding:sharding-rule>
    </sharding:data-source>
</beans>

Use DataSource in Spring

Inject DataSource to use; or configure DataSource in JPA, Hibernate or MyBatis to use.

@Resource
private DataSource dataSource;

Rule configurations include data source configuration, table rule configuration, database sharding strategy and table sharding strategy. All these are the simplest configuration methods, and the practical use can be more flexible, like multiple sharding keys, table rule configuration bound directly with sharding strategies, etc. For more detailed configurations, please refer to Configuration Manual.