实现方式一

使用若依文档中的多数据源配置

在application-druid.yml配置从库数据源

# 数据源配置
spring:
    datasource:
        type: com.alibaba.druid.pool.DruidDataSource
        driverClassName: com.mysql.cj.jdbc.Driver
        druid:
            # 主库数据源
            master:
                url: jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
                username: 账号
                password: 密码
            # 从库数据源
            slave:
                # 从数据源开关/默认关闭
                # 默认不启用TDengine，true=启用，false=不启用
                enabled: true
#                driverClassName: com.taosdata.jdbc.TSDBDriver
#                url: jdbc:TAOS://tdengine-server:6030/数据库名?timezone=Asia/Beijing&charset=utf-8
#                username: 账号
#                password: 密码
                driverClassName: com.taosdata.jdbc.rs.RestfulDriver
                url: jdbc:TAOS-RS://tdengine-server:6041/数据库名?timezone=Asia/Beijing&charset=utf-8
                username: 账号
                password: 密码

            # 初始连接数
            initialSize: 5
            # 最小连接池数量
            minIdle: 10
            # 最大连接池数量
            maxActive: 20
            # 配置获取连接等待超时的时间
            maxWait: 60000
            # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
            timeBetweenEvictionRunsMillis: 60000
            # 配置一个连接在池中最小生存的时间，单位是毫秒
            minEvictableIdleTimeMillis: 300000
            # 配置一个连接在池中最大生存的时间，单位是毫秒
            maxEvictableIdleTimeMillis: 900000
            # 配置检测连接是否有效
            validationQuery: SELECT 1 # SELECT 1 FROM DUAL 不使用全查询，如果使用tdengine多数据源报数据库不存在错误
            testWhileIdle: true
            testOnBorrow: false
            testOnReturn: false
            webStatFilter:
                enabled: true
            statViewServlet:
                enabled: true
                # 设置白名单，不填则允许所有访问
                allow:
                url-pattern: /druid/*
                # 控制台管理用户名和密码
                login-username: ids
                login-password: 123456
            filter:
                stat:
                    enabled: true
                    # 慢SQL记录
                    log-slow-sql: true
                    slow-sql-millis: 1000
                    merge-sql: false #设为false tdengine sql才能运行成功
                wall:
                    config:
                        multi-statement-allow: true

多数据源使用

在需要多数据源的方法或类上加入@DataSource注解

@Service
@DataSource(DataSourceType.SLAVE)
public class testServiceImpl implements testService
{
...
}

注意事项

1.在插入数据时需要设置useGeneratedKeys参数，否则会报数据库不存在错误。原因为ruoyi-vue在mybatis-config.xml文件全局开启了主键id自增，tdengine不支持id自增功能。

<insert id="insertData" useGeneratedKeys="false">
</insert>

2.注意多数据源文件配置中参数的变化，否则也会出现相应的报错或者sql执行不成功等情况
3.ruoyi-vue版本为3.8.5
4.tdengine使用restful方式连接无需安装客户端，若使用原生连接需要保证客户端与数据库版本的一致性

实现方式二

自定义数据源

在application-druid.yml配置从库数据源

# 数据源配置
spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: com.mysql.cj.jdbc.Driver
    druid:
      # 主库数据源
      master:
        url: jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
        username: 账号
        password: 密码
      # 从库数据源
      slave:
        # 从数据源开关/默认关闭
        enabled: false

      # TDengine数据库
      tdengine-server:
        # 默认不启用TDengine，true=启用，false=不启用
#        enabled: true
#        driverClassName: com.taosdata.jdbc.rs.RestfulDriver
#        url: jdbc:TAOS-RS://tdengine-server:6041/数据库名?timezone=Asia/Beijing&charset=utf-8
#        username: 账号
#        password: 密码
#        dbName: 数据库名 #非必要，自定义使用
        enabled: true
        driverClassName: com.taosdata.jdbc.TSDBDriver
        url: jdbc:TAOS://tdengine-server:6030/数据库名?timezone=Asia/Beijing&charset=utf-8
        username: 账号
        password: 密码
        dbName: 数据库名 #非必要，自定义使用

      # 初始连接数
      initialSize: 5
      # 最小连接池数量
      minIdle: 10
      # 最大连接池数量
      maxActive: 20
      # 配置获取连接等待超时的时间
      maxWait: 60000
      # 配置连接超时时间
      connectTimeout: 30000
      # 配置网络超时时间
      socketTimeout: 60000
      # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
      timeBetweenEvictionRunsMillis: 60000
      # 配置一个连接在池中最小生存的时间，单位是毫秒
      minEvictableIdleTimeMillis: 300000
      # 配置一个连接在池中最大生存的时间，单位是毫秒
      maxEvictableIdleTimeMillis: 900000
      # 配置检测连接是否有效
      validationQuery: SELECT 1 FROM DUAL
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      webStatFilter:
        enabled: true
      statViewServlet:
        enabled: true
        # 设置白名单，不填则允许所有访问
        allow:
        url-pattern: /druid/*
        # 控制台管理用户名和密码
        login-username: ruoyi
        login-password: 123456
      filter:
        stat:
          enabled: true
          # 慢SQL记录
          log-slow-sql: true
          slow-sql-millis: 1000
          merge-sql: true
        wall:
          config:
            multi-statement-allow: true

添加TDengineConfig配置文件

import com.alibaba.druid.pool.DruidDataSource;
import com.ruoyi.common.utils.StringUtils;
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.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

import javax.sql.DataSource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

@Configuration
@MapperScan(basePackages = {"com.ruoyi.iot.tdengine.dao"}, sqlSessionTemplateRef = "tdengineSqlSessionTemplate")
@ConditionalOnProperty(name = "spring.datasource.druid.tdengine-server.enabled", havingValue = "true")
public class TDengineConfig {

    @Value("${spring.datasource.druid.tdengine-server.dbName}")
    private String dbName;
    @Value("${spring.datasource.druid.tdengine-server.url}")
    private String jdbc;


    @Bean(name = "tDengineDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.tdengine-server")
    public DataSource tdengineDataSource() {
        return new DruidDataSource();
    }



    @Bean(name = "tDengineSqlSessionFactory")
    public SqlSessionFactory tDengineSqlSessionFactory(@Qualifier("tDengineDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setMapperLocations(resolveMapperLocations(StringUtils.split("classpath:mapper/tdengine/*Mapper.xml", ",")));
        sqlSessionFactoryBean.setDataSource(dataSource);
        return sqlSessionFactoryBean.getObject();
    }


    @Bean(name = "tdengineSqlSessionTemplate")
    public SqlSessionTemplate tdengineSqlSessionTemplate(@Qualifier("tDengineSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    public String getDbName() {
        return dbName;
    }

    public void setDbName(String dbName) {
        this.dbName = dbName;
    }
    public Resource[] resolveMapperLocations(String[] mapperLocations)
    {
        ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
        List<Resource> resources = new ArrayList<Resource>();
        if (mapperLocations != null)
        {
            for (String mapperLocation : mapperLocations)
            {
                try
                {
                    Resource[] mappers = resourceResolver.getResources(mapperLocation);
                    resources.addAll(Arrays.asList(mappers));
                }
                catch (IOException e)
                {
                    // ignore
                }
            }
        }
        return resources.toArray(new Resource[resources.size()]);
    }
}

修改MyBatisConfig文件

package com.ruoyi.framework.config;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import javax.sql.DataSource;
import org.apache.ibatis.io.VFS;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.boot.autoconfigure.SpringBootVFS;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.env.Environment;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.util.ClassUtils;
import com.ruoyi.common.utils.StringUtils;

/**
 * Mybatis支持*匹配扫描包
 *
 * @author ruoyi
 */
@Configuration
public class MyBatisConfig
{
    @Autowired
    private Environment env;

    static final String DEFAULT_RESOURCE_PATTERN = "**/*.class";

    public static String setTypeAliasesPackage(String typeAliasesPackage)
    {
        ResourcePatternResolver resolver = (ResourcePatternResolver) new PathMatchingResourcePatternResolver();
        MetadataReaderFactory metadataReaderFactory = new CachingMetadataReaderFactory(resolver);
        List<String> allResult = new ArrayList<String>();
        try
        {
            for (String aliasesPackage : typeAliasesPackage.split(","))
            {
                List<String> result = new ArrayList<String>();
                aliasesPackage = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
                        + ClassUtils.convertClassNameToResourcePath(aliasesPackage.trim()) + "/" + DEFAULT_RESOURCE_PATTERN;
                Resource[] resources = resolver.getResources(aliasesPackage);
                if (resources != null && resources.length > 0)
                {
                    MetadataReader metadataReader = null;
                    for (Resource resource : resources)
                    {
                        if (resource.isReadable())
                        {
                            metadataReader = metadataReaderFactory.getMetadataReader(resource);
                            try
                            {
                                result.add(Class.forName(metadataReader.getClassMetadata().getClassName()).getPackage().getName());
                            }
                            catch (ClassNotFoundException e)
                            {
                                e.printStackTrace();
                            }
                        }
                    }
                }
                if (result.size() > 0)
                {
                    HashSet<String> hashResult = new HashSet<String>(result);
                    allResult.addAll(hashResult);
                }
            }
            if (allResult.size() > 0)
            {
                typeAliasesPackage = String.join(",", (String[]) allResult.toArray(new String[0]));
            }
            else
            {
                throw new RuntimeException("mybatis typeAliasesPackage 路径扫描错误,参数typeAliasesPackage:" + typeAliasesPackage + "未找到任何包");
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return typeAliasesPackage;
    }

    public Resource[] resolveMapperLocations(String[] mapperLocations)
    {
        ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
        List<Resource> resources = new ArrayList<Resource>();
        if (mapperLocations != null)
        {
            for (String mapperLocation : mapperLocations)
            {
                try
                {
                    Resource[] mappers = resourceResolver.getResources(mapperLocation);
                    resources.addAll(Arrays.asList(mappers));
                }
                catch (IOException e)
                {
                    // ignore
                }
            }
        }
        return resources.toArray(new Resource[resources.size()]);
    }

    @Bean(name = "mysqlSessionFactory")
    @Primary
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception
    {
        String typeAliasesPackage = env.getProperty("mybatis.typeAliasesPackage");
        String mapperLocations = env.getProperty("mybatis.mapperLocations");
        String configLocation = env.getProperty("mybatis.configLocation");
        typeAliasesPackage = setTypeAliasesPackage(typeAliasesPackage);
        VFS.addImplClass(SpringBootVFS.class);

        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setTypeAliasesPackage(typeAliasesPackage);
        sessionFactory.setMapperLocations(resolveMapperLocations(StringUtils.split(mapperLocations, ",")));
        sessionFactory.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));
        return sessionFactory.getObject();
    }

    @Bean(name = "mysqlTransactionManager")
    @Primary
    public DataSourceTransactionManager mysqlTransactionManager(@Qualifier("dynamicDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean(name = "mysqlSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate mysqlSqlSessionTemplate(@Qualifier("mysqlSessionFactory") SqlSessionFactory sqlSessionFactory)  {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

注意事项

1.tdengine的mapper不要和ruoyi相关mapper放在同一个目录，也不要叫mapper会和mybatis扫描路径冲突。