177 lines
5.1 KiB
Markdown
177 lines
5.1 KiB
Markdown
# JeecgBoot ShardingSphere配置使用说明
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## 项目中的ShardingSphere配置
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本项目使用ShardingSphere实现分库分表功能，主要涉及以下配置文件和组件：
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## 1. 配置文件说明
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### sharding.yaml - 基础分表配置
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```yaml
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databaseName: sharding-db # 重要：必须与@DS注解中的名称一致
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dataSources:
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ds0:
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dataSourceClassName: com.zaxxer.hikari.HikariDataSource
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driverClassName: com.mysql.cj.jdbc.Driver
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jdbcUrl: jdbc:mysql://localhost:3306/jeecg-boot?useSSL=false&useUnicode=true&characterEncoding=utf-8
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username: root
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password: root
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rules:
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- !SHARDING
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tables:
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sys_log: # 分表的逻辑表名
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actualDataNodes: ds0.sys_log$->{0..1} # 实际表：sys_log0, sys_log1
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tableStrategy:
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standard:
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shardingColumn: log_type # 分片字段
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shardingAlgorithmName: table_inline
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shardingAlgorithms:
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table_inline:
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type: INLINE
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props:
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algorithm-expression: sys_log$->{log_type % 2} # 根据log_type取模分表
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```
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### sharding-multi.yaml - 分库分表+读写分离配置
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```yaml
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databaseName: sharding-db # 与@DS注解保持一致
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dataSources:
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ds0: # 主库
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jdbcUrl: jdbc:mysql://localhost:3306/jeecg-boot?...
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ds1: # 从库
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jdbcUrl: jdbc:mysql://localhost:3306/jeecg-boot2?...
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rules:
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- !SHARDING
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tables:
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sys_log:
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actualDataNodes: ds$->{0..1}.sys_log$->{0..1} # 2库2表
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databaseStrategy: # 分库策略
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standard:
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shardingColumn: operate_type
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shardingAlgorithmName: database-inline
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tableStrategy: # 分表策略
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standard:
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shardingColumn: log_type
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shardingAlgorithmName: table-classbased
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- !READWRITE_SPLITTING # 读写分离
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dataSources:
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prds:
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writeDataSourceName: ds0 # 写库
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readDataSourceNames: [ds1] # 读库
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```
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## 2. Spring Boot配置
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### application-dev.yml中的数据源配置
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```yaml
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spring:
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datasource:
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dynamic:
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datasource:
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# 普通数据源
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master:
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url: jdbc:mysql://localhost:3306/jeecg-boot
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username: root
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password: root
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# ShardingSphere分片数据源
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sharding-db: # 数据源名称，对应@DS("sharding-db")
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driver-class-name: org.apache.shardingsphere.driver.ShardingSphereDriver
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# 本地配置文件方式
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url: jdbc:shardingsphere:classpath:sharding.yaml
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# 或者Nacos配置方式
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url: jdbc:shardingsphere:nacos:sharding.yaml?serverAddr=${spring.cloud.nacos.config.server-addr}&namespace=${spring.cloud.nacos.config.namespace}&group=${spring.cloud.nacos.config.group}
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```
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**关键点：**
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- `sharding-db` 是数据源的名称标识
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- 这个名称必须与Service类上的`@DS("sharding-db")`注解保持一致
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## 3. Service层使用
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### ShardingSysLogServiceImpl类配置
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```java
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@Service
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@DS("sharding-db") // 指定使用sharding-db数据源
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public class ShardingSysLogServiceImpl extends ServiceImpl<ShardingSysLogMapper, ShardingSysLog>
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implements IShardingSysLogService {
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}
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```
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**配置关系说明：**
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1. `@DS("sharding-db")` 注解告诉MyBatis-Plus使用名为`sharding-db`的数据源
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2. `sharding-db`对应application-dev.yml中配置的数据源名称
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3. 该数据源使用ShardingSphere驱动，会根据sharding.yaml中的规则进行分片
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## 4. 使用步骤
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### 步骤1：准备数据库表
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```sql
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-- 在jeecg-boot数据库中创建分表
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CREATE TABLE sys_log0 LIKE sys_log;
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CREATE TABLE sys_log1 LIKE sys_log;
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```
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### 步骤2：配置application-dev.yml
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```yaml
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spring:
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datasource:
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dynamic:
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datasource:
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sharding-db:
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driver-class-name: org.apache.shardingsphere.driver.ShardingSphereDriver
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url: jdbc:shardingsphere:classpath:sharding.yaml
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```
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### 步骤3：配置sharding.yaml
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- 将配置文件放在`src/main/resources/`目录下
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- 确保`databaseName: sharding-db`与数据源名称一致
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### 步骤4：在Service上添加注解
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```java
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@DS("sharding-db") // 使用分片数据源
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public class ShardingSysLogServiceImpl {
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// 业务代码
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}
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```
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### 步骤5：正常使用MyBatis-Plus
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```java
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// 插入数据时会自动根据log_type字段进行分表
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shardingSysLogService.save(sysLog);
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// 查询时也会根据分片规则路由到正确的表
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shardingSysLogService.list();
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```
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## 5. 配置验证
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启动项目后查看日志，如果看到类似输出说明配置成功：
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```
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Logic SQL: INSERT INTO sys_log (log_type, content) VALUES (?, ?)
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Actual SQL: ds0 ::: INSERT INTO sys_log0 (log_type, content) VALUES (?, ?)
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```
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## 6. 注意事项
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1. **名称一致性**：确保以下三处名称完全一致
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- application-dev.yml中的数据源名称：`sharding-db`
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- sharding.yaml中的databaseName：`sharding-db`
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- Service类注解：`@DS("sharding-db")`
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2. **表结构一致**：所有分片表的结构必须完全一致
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3. **分片键选择**：选择分布均匀的字段作为分片键，避免数据倾斜
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4. **事务支持**：单表事务正常，跨表事务需要注意
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这样配置后，通过ShardingSysLogServiceImpl操作的数据会自动根据分片规则分布到不同的表中。
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