JAVA+MySQL实现分库分表的项目实践

<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
    <version>5.1.0</version>
</dependency>

spring:
  shardingsphere:
    datasource:
      names: ds0, ds1, ds2, ds3
      ds0:
        url: jdbc:mysql://localhost:3306/db0
        username: root
        password: root
      ds1:
        url: jdbc:mysql://localhost:3306/db1
        username: root
        password: root
      ds2:
        url: jdbc:mysql://localhost:3306/db2
        username: root
        password: root
      ds3:
        url: jdbc:mysql://localhost:3306/db3
        username: root
        password: root
    sharding:
      tables:
        user:
          actual-data-nodes: ds$->{0..3}.user_$->{0..3}
          table-strategy:
            inline:
              sharding-column: user_id
              algorithm-expression: user_$->{user_id % 4}
          database-strategy:
            inline:
              sharding-column: user_id
              algorithm-expression: ds$->{user_id % 4}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

@Service
public class UserService {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void addUser(Long userId, String username) {
        String sql = "INSERT INTO user (user_id, username) VALUES (?, ?)";
        jdbcTemplate.update(sql, userId, username);
    }

    public String getUser(Long userId) {
        String sql = "SELECT username FROM user WHERE user_id = ?";
        return jdbcTemplate.queryForObject(sql, new Object[]{userId}, String.class);
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class ShardingApplication implements CommandLineRunner {

    @Autowired
    private UserService userService;

    public static void main(String[] args) {
        SpringApplication.run(ShardingApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        userService.addUser(1L, "user1");
        userService.addUser(2L, "user2");
        userService.addUser(3L, "user3");
        userService.addUser(4L, "user4");

        System.out.println("User 1: " + userService.getUser(1L));
        System.out.println("User 2: " + userService.getUser(2L));
        System.out.println("User 3: " + userService.getUser(3L));
        System.out.println("User 4: " + userService.getUser(4L));
    }
}