数据分片

不使用Spring

引入Maven依赖

  1. <dependency>
  2.     <groupId>org.apache.shardingsphere</groupId>
  3.     <artifactId>sharding-jdbc-core</artifactId>
  4.     <version>${sharding-sphere.version}</version>
  5. </dependency>

基于Java编码的规则配置

Sharding-JDBC的分库分表通过规则配置描述，以下例子是根据user_id取模分库, 且根据order_id取模分表的两库两表的配置。

  1.     // 配置真实数据源
  2.     Map<String, DataSource> dataSourceMap = new HashMap<>();
  4.     // 配置第一个数据源
  5.     BasicDataSource dataSource1 = new BasicDataSource();
  6.     dataSource1.setDriverClassName("com.mysql.jdbc.Driver");
  7.     dataSource1.setUrl("jdbc:mysql://localhost:3306/ds0");
  8.     dataSource1.setUsername("root");
  9.     dataSource1.setPassword("");
  10.     dataSourceMap.put("ds0", dataSource1);
  12.     // 配置第二个数据源
  13.     BasicDataSource dataSource2 = new BasicDataSource();
  14.     dataSource2.setDriverClassName("com.mysql.jdbc.Driver");
  15.     dataSource2.setUrl("jdbc:mysql://localhost:3306/ds1");
  16.     dataSource2.setUsername("root");
  17.     dataSource2.setPassword("");
  18.     dataSourceMap.put("ds1", dataSource2);
  20.     // 配置Order表规则
  21.     TableRuleConfiguration orderTableRuleConfig = new TableRuleConfiguration("t_order","ds${0..1}.t_order${0..1}");
  23.     // 配置分库 + 分表策略
  24.     orderTableRuleConfig.setDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("user_id", "ds${user_id % 2}"));
  25.     orderTableRuleConfig.setTableShardingStrategyConfig(new InlineShardingStrategyConfiguration("order_id", "t_order${order_id % 2}"));
  27.     // 配置分片规则
  28.     ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
  29.     shardingRuleConfig.getTableRuleConfigs().add(orderTableRuleConfig);
  31.     // 省略配置order_item表规则...
  32.     // ...
  34.     // 获取数据源对象
  35.     DataSource dataSource = ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig, new Properties());

基于Yaml的规则配置

或通过Yaml方式配置，与以上配置等价：

  1. dataSources:
  2.   ds0: !!org.apache.commons.dbcp.BasicDataSource
  3.     driverClassName: com.mysql.jdbc.Driver
  4.     url: jdbc:mysql://localhost:3306/ds0
  5.     username: root
  6.     password: 
  7.   ds1: !!org.apache.commons.dbcp.BasicDataSource
  8.     driverClassName: com.mysql.jdbc.Driver
  9.     url: jdbc:mysql://localhost:3306/ds1
  10.     username: root
  11.     password: 
  13. shardingRule:
  14.   tables:
  15.     t_order: 
  16.       actualDataNodes: ds${0..1}.t_order${0..1}
  17.       databaseStrategy: 
  18.         inline:
  19.           shardingColumn: user_id
  20.           algorithmExpression: ds${user_id % 2}
  21.       tableStrategy: 
  22.         inline:
  23.           shardingColumn: order_id
  24.           algorithmExpression: t_order${order_id % 2}
  25.     t_order_item: 
  26.       actualDataNodes: ds${0..1}.t_order_item${0..1}
  27.       databaseStrategy: 
  28.         inline:
  29.           shardingColumn: user_id
  30.           algorithmExpression: ds${user_id % 2}
  31.       tableStrategy: 
  32.         inline:
  33.           shardingColumn: order_id
  34.           algorithmExpression: t_order_item${order_id % 2}
  1.     DataSource dataSource = YamlShardingDataSourceFactory.createDataSource(yamlFile);

使用原生JDBC

通过ShardingDataSourceFactory或者YamlShardingDataSourceFactory工厂和规则配置对象获取ShardingDataSource，ShardingDataSource实现自JDBC的标准接口DataSource。然后可通过DataSource选择使用原生JDBC开发，或者使用JPA, MyBatis等ORM工具。以JDBC原生实现为例：

  1. DataSource dataSource = YamlShardingDataSourceFactory.createDataSource(yamlFile);
  2. 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=?";
  3. try (
  4.         Connection conn = dataSource.getConnection();
  5.         PreparedStatement preparedStatement = conn.prepareStatement(sql)) {
  6.     preparedStatement.setInt(1, 10);
  7.     preparedStatement.setInt(2, 1001);
  8.     try (ResultSet rs = preparedStatement.executeQuery()) {
  9.         while(rs.next()) {
  10.             System.out.println(rs.getInt(1));
  11.             System.out.println(rs.getInt(2));
  12.         }
  13.     }
  14. }

使用Spring

引入Maven依赖

  1. <!-- for spring boot -->
  2. <dependency>
  3.     <groupId>org.apache.shardingsphere</groupId>
  4.     <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
  5.     <version>${sharding-sphere.version}</version>
  6. </dependency>
  8. <!-- for spring namespace -->
  9. <dependency>
  10.     <groupId>org.apache.shardingsphere</groupId>
  11.     <artifactId>sharding-jdbc-spring-namespace</artifactId>
  12.     <version>${sharding-sphere.version}</version>
  13. </dependency>

基于Spring boot的规则配置

  1. spring.shardingsphere.datasource.names=ds0,ds1
  3. spring.shardingsphere.datasource.ds0.type=org.apache.commons.dbcp2.BasicDataSource
  4. spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
  5. spring.shardingsphere.datasource.ds0.url=jdbc:mysql://localhost:3306/ds0
  6. spring.shardingsphere.datasource.ds0.username=root
  7. spring.shardingsphere.datasource.ds0.password=
  9. spring.shardingsphere.datasource.ds1.type=org.apache.commons.dbcp2.BasicDataSource
  10. spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
  11. spring.shardingsphere.datasource.ds1.url=jdbc:mysql://localhost:3306/ds1
  12. spring.shardingsphere.datasource.ds1.username=root
  13. spring.shardingsphere.datasource.ds1.password=
  15. spring.shardingsphere.sharding.default-database-strategy.inline.sharding-column=user_id
  16. spring.shardingsphere.sharding.default-database-strategy.inline.algorithm-expression=ds$->{user_id % 2}
  18. spring.shardingsphere.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{0..1}
  19. spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column=order_id
  20. spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.algorithm-expression=t_order$->{order_id % 2}
  22. spring.shardingsphere.sharding.tables.t_order_item.actual-data-nodes=ds$->{0..1}.t_order_item$->{0..1}
  23. spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.sharding-column=order_id
  24. spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.algorithm-expression=t_order_item$->{order_id % 2}

基于Spring boot + JNDI的规则配置

如果您计划使用Spring boot + JNDI的方式，在应用容器（如Tomcat）中使用Sharding-JDBC时，可使用spring.shardingsphere.datasource.${datasourceName}.jndiName来代替数据源的一系列配置。如：

  1. spring.shardingsphere.datasource.names=ds0,ds1
  3. spring.shardingsphere.datasource.ds0.jndi-name=java:comp/env/jdbc/ds0
  4. spring.shardingsphere.datasource.ds1.jndi-name=jdbc/ds1
  6. spring.shardingsphere.sharding.default-database-strategy.inline.sharding-column=user_id
  7. spring.shardingsphere.sharding.default-database-strategy.inline.algorithm-expression=ds$->{user_id % 2}
  9. spring.shardingsphere.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{0..1}
  10. spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column=order_id
  11. spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.algorithm-expression=t_order$->{order_id % 2}
  13. spring.shardingsphere.sharding.tables.t_order_item.actual-data-nodes=ds$->{0..1}.t_order_item$->{0..1}
  14. spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.sharding-column=order_id
  15. spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.algorithm-expression=t_order_item$->{order_id % 2}

基于Spring命名空间的规则配置

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <beans xmlns="http://www.springframework.org/schema/beans"
  3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  4.     xmlns:sharding="http://shardingsphere.apache.org/schema/shardingsphere/sharding" 
  5.     xsi:schemaLocation="http://www.springframework.org/schema/beans 
  6.                         http://www.springframework.org/schema/beans/spring-beans.xsd
  7.                         http://shardingsphere.apache.org/schema/shardingsphere/sharding 
  8.                         http://shardingsphere.apache.org/schema/shardingsphere/sharding/sharding.xsd 
  9.                         ">
  10.     <bean id="ds0" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
  11.         <property name="driverClassName" value="com.mysql.jdbc.Driver" />
  12.         <property name="url" value="jdbc:mysql://localhost:3306/ds0" />
  13.         <property name="username" value="root" />
  14.         <property name="password" value="" />
  15.     </bean>
  16.     <bean id="ds1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
  17.         <property name="driverClassName" value="com.mysql.jdbc.Driver" />
  18.         <property name="url" value="jdbc:mysql://localhost:3306/ds1" />
  19.         <property name="username" value="root" />
  20.         <property name="password" value="" />
  21.     </bean>
  23.     <sharding:inline-strategy id="databaseStrategy" sharding-column="user_id" algorithm-expression="ds$->{user_id % 2}" />
  24.     <sharding:inline-strategy id="orderTableStrategy" sharding-column="order_id" algorithm-expression="t_order$->{order_id % 2}" />
  25.     <sharding:inline-strategy id="orderItemTableStrategy" sharding-column="order_id" algorithm-expression="t_order_item$->{order_id % 2}" />
  27.     <sharding:data-source id="shardingDataSource">
  28.         <sharding:sharding-rule data-source-names="ds0,ds1">
  29.             <sharding:table-rules>
  30.                 <sharding:table-rule logic-table="t_order" actual-data-nodes="ds$->{0..1}.t_order$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderTableStrategy" />
  31.                 <sharding:table-rule logic-table="t_order_item" actual-data-nodes="ds$->{0..1}.t_order_item$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderItemTableStrategy" />
  32.             </sharding:table-rules>
  33.         </sharding:sharding-rule>
  34.     </sharding:data-source>
  35. </beans>

在Spring中使用DataSource

直接通过注入的方式即可使用DataSource，或者将DataSource配置在JPA、Hibernate或MyBatis中使用。

  1. @Resource
  2. private DataSource dataSource;

规则配置包括数据源配置、表规则配置、分库策略和分表策略组成。这只是最简单的配置方式，实际使用可更加灵活，如：多分片键，分片策略直接和表规则配置绑定等。更多的详细配置请参考配置手册。