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Sharding-JDBC-分库分表-使用

2024-09-09 数据库 11756

简介

本文用示例介绍Sharding-JDBC分库分表的方法。

实战

依赖：sharding-jdbc-spring-boot-starter4.4.1，mybatis-plus3.4.1。

注意：不要参考官网的文档，官网文档可能没更新，配置根本无效。

源码下载

下载地址

建库建表

建库

创建两个库：sharding-jdbc0、sharding-jdbc1

建表

在上边两个库里按下边这个结构创建表，以t_order_0和t_order_1命名。

CREATE TABLE `t_order`  (
  `id` bigint(11) NOT NULL AUTO_INCREMENT,
  `user_id` bigint(11) NULL DEFAULT NULL COMMENT '用户id',
  `product_id` bigint(11) NULL DEFAULT NULL COMMENT '产品id',
  `count` int(11) NULL DEFAULT NULL COMMENT '数量',
  `money` decimal(11, 0) NULL DEFAULT NULL COMMENT '金额',
  `status` int(1) NULL DEFAULT NULL COMMENT '订单状态：0：创建中；1：已完结',
  `create_time` datetime(0) NULL DEFAULT NULL,
  `update_time` datetime(0) NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP(0),
  PRIMARY KEY (`id`)
) ENGINE = InnoDB;

结果

依赖与配置

依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <!-- <version>8.0.21</version> 版本Spring-Boot-Parent中已带 -->
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.apache.shardingsphere/sharding-jdbc-spring-boot-starter -->
        <dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <version>4.1.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

配置

application.yml

server:
  port: 9011

spring:
  application:
    name: order
  #  datasource:
  #    driver-class-name: com.mysql.cj.jdbc.Driver
  #    url: jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
  #    username: root
  #    password: 222333
  profiles:
    include: sharding_jdbc

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

applicaiton-sharding_jdbc.yml

spring:
  shardingsphere:
    datasource:
      names: ds0,ds1
      ds0:
        driver-class-name: com.mysql.cj.jdbc.Driver
        jdbc-url: jdbc:mysql://127.0.0.1:3306/sharding-jdbc0?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
        username: root
        password: 222333
        type: com.zaxxer.hikari.HikariDataSource
      ds1:
        driver-class-name: com.mysql.cj.jdbc.Driver
        jdbc-url: jdbc:mysql://127.0.0.1:3306/sharding-jdbc1?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
        username: root
        password: 222333
        type: com.zaxxer.hikari.HikariDataSource
    sharding:
      tables:
        t_order:
          #key-generator:
          #  column: id
          #  type: SNOWFLAKE
          actual-data-nodes: ds$->{0..1}.t_order_$->{0..1}
          database-strategy:
            inline:
              sharding-column: id
              algorithm-expression: ds$->{id % 2}
          table-strategy:
            inline:
              sharding-column: id
              algorithm-expression: t_order_$->{id % 2}
    props:
      sql:
        show: true   # 日志显示SQL

代码

Controller

package com.example.demo.controller;

import com.example.demo.entity.Order;
import com.example.demo.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/*
http://localhost:9011/order/onlyCreateOrder?userId=1&productId=1&count=10&money=100
*/
@RestController
@RequestMapping("/order")
public class OrderController {
    @Autowired
    OrderService orderService;

    private Long id = 1L;

    //只保存订单
    @PostMapping("onlyCreateOrder")
    @Transactional
    public String onlyCreateOrder(Order order) {
        order.setId(id++);
        orderService.save(order);
        return "success";
    }

    //只保存订单
    @PostMapping("onlyCreateOrderError")
    @Transactional
    public String onlyCreateOrderError(Order order) {
        order.setId(id++);
        orderService.save(order);
        order.setId(id++);
        orderService.save(order);
        int i = 1 / 0;
        return "success";
    }
}

entity

注意：id必须是IdType.INPUT类型。如果是IdType.AUTO，则不会按照预期执行，结果会是：在所有的库表里（本处是：ds0.t_order_0、ds0.t_order_1，ds1.t_order_0、ds1.t_order_1）都会操作（本处是插入数据）。

package com.example.demo.entity;

import com.baomidou.mybatisplus.annotation.*;
import lombok.Data;
import lombok.EqualsAndHashCode;

import java.math.BigDecimal;
import java.time.LocalDateTime;

@Data
@EqualsAndHashCode(callSuper = false)
@TableName("t_order")
public class Order{
    @TableId(value = "id", type = IdType.INPUT)
    private Long id;

    // 用户id
    private Long userId;

    // 产品id
    private Long productId;

    // 数量
    private Integer count;

    // 金额
    private BigDecimal money;

    // 订单状态：0：创建中；1：已完结
    private Integer status;

    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;

    // 插入与更新都写此字段。若使用FieldFill.UPDATE，则只更新时写此字段。
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;

    public Order(Long id, Long userId, Long productId, Integer count, BigDecimal money, Integer status) {
        this.id = id;
        this.userId = userId;
        this.productId = productId;
        this.count = count;
        this.money = money;
        this.status = status;
    }
}

mapper

package com.example.demo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.Order;
import org.springframework.stereotype.Repository;

@Repository
public interface OrderMapper extends BaseMapper<Order> {
}

测试

正常执行

访问：http://localhost:9011/order/onlyCreateOrder?userId=1&productId=1&count=10&money=100

结果：

再次访问：http://localhost:9011/order/onlyCreateOrder?userId=1&productId=1&count=10&money=100

结果：

抛出异常  （支持事务）

访问：http://localhost:9011/order/onlyCreateOrderError?userId=1&productId=1&count=10&money=100

结果：

抛出异常，没有数据插入。 ​

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