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

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

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.20</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <version>4.0.0-RC1</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

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

@Data
public class Course {
    private Long cid;
    private String cname;
    private Long userId;
    private String cstatus;
}



@Repository
public interface CourseMapper extends BaseMapper<Course> {
}

#sharding-jdbc 分片策略
# 数据源名称，多数据源以逗号分隔
# 水平分库，所以要配置多数据源
spring.shardingsphere.datasource.names=m1,m2

#一个实体类对应两张表
spring.main.allow-bean-definition-overriding=true

# 第一个数据源
# 数据库连接池
spring.shardingsphere.datasource.m1.type=com.alibaba.druid.pool.DruidDataSource
#数据库驱动类名
spring.shardingsphere.datasource.m1.driver-class-name= com.mysql.cj.jdbc.Driver
# 数据库 URL 连接
spring.shardingsphere.datasource.m1.url=jdbc:mysql://localhost:3306/edu_db_1?serverTimezone=GMT%2B8
# 数据库用户名
spring.shardingsphere.datasource.m1.username= root
# 数据库密码
spring.shardingsphere.datasource.m1.password=houchen

# 第二个数据源
# 数据库连接池
spring.shardingsphere.datasource.m2.type=com.alibaba.druid.pool.DruidDataSource
#数据库驱动类名
spring.shardingsphere.datasource.m2.driver-class-name= com.mysql.cj.jdbc.Driver
# 数据库 URL 连接
spring.shardingsphere.datasource.m2.url=jdbc:mysql://localhost:3306/edu_db_2?serverTimezone=GMT%2B8
# 数据库用户名
spring.shardingsphere.datasource.m2.username= root
# 数据库密码
spring.shardingsphere.datasource.m2.password=houchen


# 指定数据库的分布情况 数据库里面表的分布情况
spring.shardingsphere.sharding.tables.course.actual-data-nodes=m$->{1..2}.course_$->{1..2}


#指定course表中主键的生成策略  SNOWFLAKE:雪花算法
spring.shardingsphere.sharding.tables.course.key-generator.column = cid
spring.shardingsphere.sharding.tables.course.key-generator.type =SNOWFLAKE

# 指定数据表分片的策略 约定cid值 ： 偶数--》course_1  奇数-->course_2
spring.shardingsphere.sharding.tables.course.table-strategy.inline.sharding-column= cid
spring.shardingsphere.sharding.tables.course.table-strategy.inline.algorithm-expression=course_$->{cid%2 +1}

# 指定数据库分片的策略  约定：user_id是偶数，则将数据添加到m1的数据库中  user_id是奇数，则将数据添加到m2的数据库中
#spring.shardingsphere.sharding.default-database-strategy.inline.sharding-column= user_id
#spring.shardingsphere.sharding.default-database-strategy.inline.algorithm-expression=m$->{user_id%2+1}

spring.shardingsphere.sharding.tables.course.database-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.tables.course.database-strategy.inline.algorithm-expression=m$->{user_id%2+1}

#打开sql的输出日志
spring.shardingsphere.props.sql.show = true

@RunWith(SpringRunner.class)
@SpringBootTest
public class ShardingJdbcDdemoApplicationTest {

    @Autowired
    private CourseMapper courseMapper;

    // 测试水平分库
    @Test
    public void testEduCourse(){
        Course course =new Course();
        course.setCname("java");
        course.setUserId(100L); //偶数，按照前面的配置，应该插入到m1库
        course.setCstatus("normal");
        courseMapper.insert(course);
    }
}