注意:这里不讲解seata的搭建 

这里使用的是默认的AT模式

1、加依赖

2021.0.4.0
1.6.1
3.5.2 
io.seataseata-spring-boot-starter${io.seata.version}druidcom.alibabacom.alibaba.cloudspring-cloud-starter-alibaba-seata${cloud-alibaba.version}io.seataseata-spring-boot-startercom.baomidoumybatis-plus-boot-starter${mybatis.plus.version}

2、加配置

A项目mybatis+seata配置

yml：

spring:application:name: A模块名称description: A模块描述datasource:orderdb:jdbc-url: jdbc:mysql://127.0.0.1:3306/A?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTCusername: A库password: 123456driver-class-name: com.mysql.jdbc.Driverfunddatadb:jdbc-url: jdbc:mysql://127.0.0.1:3306/B?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTCusername: B库password: 123456driver-class-name: com.mysql.jdbc.Driver#seata配置
seata:enabled: trueenable-auto-data-source-proxy: trueapplication-id: seata-cilent-deme# Seata 事务组编号，此处需于 seata 相同tx-service-group: default-tx-groupdata-source-proxy-mode: ATconfig:type: nacosnacos:# nacos ip地址server-addr: nacos地址group: DEFAULT_GROUPdata-id: seata-server.properties # 读取 nacos seata 配置namespace: nacos命名空间username: nacos账号password: nacos密码registry:type: nacosnacos:application: seata-server # seata 服务名# nacos ip地址server-addr:  nacos地址group: DEFAULT_GROUPnamespace: nacos命名空间username: nacos账号password: nacos密码

 nacos对应的seata-server.properties 配置

service.vgroupMapping.default-tx-group=default
service.enableDegrade=false
service.disableGlobalTransaction=false#Transaction storage configuration, only for the server. The file, DB, and redis configuration values are optional.
store.mode=db
store.lock.mode=db
store.session.mode=db
#Used for password encryption
store.publicKey=#These configurations are required if the `store mode` is `db`. If `store.mode,store.lock.mode,store.session.mode` are not equal to `db`, you can remove the configuration block.
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.cj.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=seata
store.db.password=123456
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table
store.db.branchTable=branch_table
store.db.distributedLockTable=distributed_lock
store.db.queryLimit=100
store.db.lockTable=lock_table
store.db.maxWait=5000#Transaction rule configuration, only for the server
server.recovery.committingRetryPeriod=1000
server.recovery.asynCommittingRetryPeriod=1000
server.recovery.rollbackingRetryPeriod=1000
server.recovery.timeoutRetryPeriod=1000
server.maxCommitRetryTimeout=-1
server.maxRollbackRetryTimeout=-1
server.rollbackRetryTimeoutUnlockEnable=false
server.distributedLockExpireTime=10000
server.xaerNotaRetryTimeout=60000
server.session.branchAsyncQueueSize=5000
server.session.enableBranchAsyncRemove=false#Transaction rule configuration, only for the client
client.rm.asyncCommitBufferLimit=10000
client.rm.lock.retryInterval=10
client.rm.lock.retryTimes=30
client.rm.lock.retryPolicyBranchRollbackOnConflict=true
client.rm.reportRetryCount=5
client.rm.tableMetaCheckEnable=true
client.rm.tableMetaCheckerInterval=60000
client.rm.sqlParserType=druid
client.rm.reportSuccessEnable=false
client.rm.sagaBranchRegisterEnable=false
client.rm.sagaJsonParser=fastjson
client.rm.tccActionInterceptorOrder=-2147482648
client.tm.commitRetryCount=5
client.tm.rollbackRetryCount=5
client.tm.defaultGlobalTransactionTimeout=60000
client.tm.degradeCheck=false
client.tm.degradeCheckAllowTimes=10
client.tm.degradeCheckPeriod=2000
client.tm.interceptorOrder=-2147482648
client.undo.dataValidation=true
client.undo.logSerialization=jackson
client.undo.onlyCareUpdateColumns=true
server.undo.logSaveDays=7
server.undo.logDeletePeriod=86400000
client.undo.logTable=undo_log
client.undo.compress.enable=true
client.undo.compress.type=zip
client.undo.compress.threshold=64k#For TCC transaction mode
tcc.fence.logTableName=tcc_fence_log
tcc.fence.cleanPeriod=1h#Log rule configuration, for client and server
log.exceptionRate=100
#Metrics configuration, only for the server
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898
#For details about configuration items, see https://seata.io/zh-cn/docs/user/configurations.html
#Transport configuration, for client and server
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableTmClientBatchSendRequest=false
transport.enableRmClientBatchSendRequest=true
transport.enableTcServerBatchSendResponse=false
transport.rpcRmRequestTimeout=30000
transport.rpcTmRequestTimeout=30000
transport.rpcTcRequestTimeout=30000
transport.threadFactory.bossThreadPrefix=NettyBoss
transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker
transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler
transport.threadFactory.shareBossWorker=false
transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector
transport.threadFactory.clientSelectorThreadSize=1
transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread
transport.threadFactory.bossThreadSize=1
transport.threadFactory.workerThreadSize=default
transport.shutdown.wait=3
transport.serialization=seata
transport.compressor=none

在所需要分布式事务的库创建undo_log表 每个数据源库都需要

CREATE TABLE `undo_log` (`id` bigint(20) NOT NULL AUTO_INCREMENT,`branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',`xid` varchar(100) NOT NULL COMMENT 'global transaction id',`context` varchar(128) NOT NULL COMMENT 'undo_log context,such as serialization',`rollback_info` longblob NOT NULL COMMENT 'rollback info',`log_status` int(11) NOT NULL COMMENT '0:normal status,1:defense status',`log_created` datetime(6) NOT NULL COMMENT 'create datetime',`log_modified` datetime(6) NOT NULL COMMENT 'modify datetime',PRIMARY KEY (`id`),UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=25 DEFAULT CHARSET=utf8mb4 COMMENT='AT transaction mode undo table';

B项目:同A项目mybatis+seata配置

........此处同A项目配置

Mybatis配置:

DataSourceOrderConfig

import com.zaxxer.hikari.HikariDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.annotation.Order;import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;@Order(5)
@Configuration
public class DataSourceOrderConfig {// @Primary@Bean(name = "orderDataSource")@ConfigurationProperties("spring.datasource.orderdb")public DataSource orderDataSource() {return DataSourceBuilder.create().type(HikariDataSource.class).build();}// @Primary@Bean(name = "funddataDataSource")@ConfigurationProperties("spring.datasource.funddatadb")public DataSource funddataDataSource() {return DataSourceBuilder.create().type(HikariDataSource.class).build();}

MybatisFundDataConfig

import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import com.zaxxer.hikari.HikariDataSource;
import io.seata.rm.datasource.DataSourceProxy;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;import javax.sql.DataSource;@Order(6)
@Configuration
@MapperScan(basePackages = {"com.hy.hyproduct.mapper.funddata"},sqlSessionTemplateRef  = "funddataSqlSessionTemplate")
public class MybatisFundDataConfig {@Bean(name = "funddataTransactionManager")//@Primarypublic DataSourceTransactionManager setTransactionManager(@Qualifier("funddataDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}@Bean(name = "funddataDataSourceProxy")public DataSourceProxy funddataDataSourceProxy(@Qualifier("funddataDataSource") DataSource dataSource) {return new DataSourceProxy(dataSource);}@Bean(name = "funddataSqlSessionFactory")//@Primarypublic SqlSessionFactory setSqlSessionFactory(@Qualifier("funddataDataSourceProxy") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();bean.setDataSource(dataSource);// 分页插件配置/* PaginationInnerInterceptor paginationInterceptor = new PaginationInnerInterceptor();bean.setPlugins(new Interceptor[]{paginationInterceptor});*/// 配置打印sql语句MybatisConfiguration configuration = new MybatisConfiguration();//configuration.setLogImpl(StdOutImpl.class);//开启驼峰命名configuration.setMapUnderscoreToCamelCase(true);bean.setConfiguration(configuration);bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/funddata/**/*.xml"));return bean.getObject();}@Bean(name = "funddataSqlSessionTemplate")@Primarypublic SqlSessionTemplate setSqlSessionTemplate(@Qualifier("funddataSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {return new SqlSessionTemplate(sqlSessionFactory);}
}

MybatisSaleOrderConfig

import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import com.zaxxer.hikari.HikariDataSource;
import io.seata.rm.datasource.DataSourceProxy;
import org.apache.ibatis.logging.stdout.StdOutImpl;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;import javax.sql.DataSource;@Order(6)
@Configuration
@MapperScan(basePackages = {"com.hy.hyproduct.mapper.funddata"},sqlSessionTemplateRef  = "funddataSqlSessionTemplate")
public class MybatisFundDataConfig {@Bean(name = "funddataTransactionManager")//@Primarypublic DataSourceTransactionManager setTransactionManager(@Qualifier("funddataDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}@Bean(name = "funddataDataSourceProxy")public DataSourceProxy funddataDataSourceProxy(@Qualifier("funddataDataSource") DataSource dataSource) {return new DataSourceProxy(dataSource);}@Bean(name = "funddataSqlSessionFactory")//@Primarypublic SqlSessionFactory setSqlSessionFactory(@Qualifier("funddataDataSourceProxy") DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean bean = new MybatisSqlSessionFactoryBean();bean.setDataSource(dataSource);// 分页插件配置/* PaginationInnerInterceptor paginationInterceptor = new PaginationInnerInterceptor();bean.setPlugins(new Interceptor[]{paginationInterceptor});*/// 配置打印sql语句MybatisConfiguration configuration = new MybatisConfiguration();//configuration.setLogImpl(StdOutImpl.class);//开启驼峰命名configuration.setMapUnderscoreToCamelCase(true);bean.setConfiguration(configuration);bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/funddata/**/*.xml"));return bean.getObject();}@Bean(name = "funddataSqlSessionTemplate")@Primarypublic SqlSessionTemplate setSqlSessionTemplate(@Qualifier("funddataSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {return new SqlSessionTemplate(sqlSessionFactory);}
}

注意以上mybatis集成seata主要是把数据源给了seata的代理类DataSourceProxy 

最后在2边的方法上面加上@GlobalTransactional注解就行了

以上代码是博主进行试验过的，可以成功退回

AT模式原理具体参考这篇文章:https://blog.csdn.net/qq_48721706/article/details/122656490