Sharding-Sphere 水平分表

逻辑表

水平拆分数据表的总称，如果真实表是t_order_1,t_order_2,....t_order_5,在进行表操作的时候并不能使用真实表名称，必须使用逻辑表名称t_order

真实表

• 数据库中真实的表

数据节点

• 数据分片的最小物理单元，有数据源名称和数据表组成

绑定表

• t_product(product_id),t_product_descrition(product_id),

• 指定分片规则一致的主表和从表

非绑定表：进行联表查询的时候会出现笛卡尔积 3 x 3 = 9

绑定表： 进行联表查询的时候不会出现笛卡尔积 3 x 3 = 3

新建一个springboot 项目

配置application.properties 文件

server.port=43210
spring.application.name = sharding-jdbc-quickstart-demo
server.servlet.context-path = /sharding-jdbc-quickstart-demo
spring.http.encoding.enabled = true
spring.http.encoding.charset = UTF-8
spring.http.encoding.force = true
mybatis.configuration.map-underscore-to-camel-case = true
#spring.profiles.active=masterslave




# 自定义数据源
spring.shardingsphere.datasource.names = m1
spring.shardingsphere.datasource.m1.type = com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.m1.driver-class-name = com.mysql.jdbc.Driver
spring.shardingsphere.datasource.m1.url = jdbc:mysql://localhost:3306/user_db?useUnicode=true&useSSL=false
spring.shardingsphere.datasource.m1username = root
spring.shardingsphere.datasource.m1.password = root

# 以下是分片规则配置
# 指定t_order表的数据分布情况，配置数据节点
# t_order 逻辑表名
# insert into t_order () values ()
# $->{1..2} => 1, 2 => t_order_1,t_order_2
spring.shardingsphere.sharding.tables.t_order.actual-data-nodes = m1.t_order_$->{1..2}
#spring.shardingsphere.sharding.tables.t_user.actual-data-nodes =ds0.t_user

# 指定t_order表的主键生成策略为SNOWFLAKE
spring.shardingsphere.sharding.tables.t_order.key-generator.column=order_id
#雪花片算法，另一种
spring.shardingsphere.sharding.tables.t_order.key-generator.type=SNOWFLAKE

# 指定t_order表的分片策略，分片策略包括分片键和分片算法
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column = order_id
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.algorithm-expression = t_order_$->{order_id % 2 + 1}


# 打开sql输出日志
spring.shardingsphere.props.sql.show = true
logging.level.root = info
#logging.level.org.springframework.web=info
#logging.level.com.itheima.dbsharding=debug
#logging.level.druid.sql=debug

mapper 文件

    @Insert("insert into t_order(price,user_id,status)values(#{price},#{userId},#{status})")
    int insertOrderInfo(@Param("price") BigDecimal price, @Param("userId")Long userId, @Param("status")String status);

test 测试类

 @Autowired
    public OrderMapper orderMapper;

    @Test
    public void testInsertOrder(){
        for (int i = 0 ; i<10; i++){
            orderMapper.insertOrderInfo(new BigDecimal((i+1)*4),1L,"Success");
        }
    }

成功界面：

 

数据库中含有t_order_1 和 t_order_1  两张表

 

DROP TABLE IF EXISTS `t_order_1`;
CREATE TABLE `t_order_1`  (
  `order_id` bigint(20) NOT NULL COMMENT '订单id',
  `price` decimal(10, 2) NOT NULL COMMENT '订单价格',
  `user_id` bigint(20) NOT NULL COMMENT '下单用户id',
  `status` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '订单状态',
  PRIMARY KEY (`order_id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Table structure for t_order_2
-- ----------------------------
DROP TABLE IF EXISTS `t_order_2`;
CREATE TABLE `t_order_2`  (
  `order_id` bigint(20) NOT NULL COMMENT '订单id',
  `price` decimal(10, 2) NOT NULL COMMENT '订单价格',
  `user_id` bigint(20) NOT NULL COMMENT '下单用户id',
  `status` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '订单状态',
  PRIMARY KEY (`order_id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;