我使用的是若依mybaits-plus，具体根据自己的情况做更改

增加其他数据库的配置 ，我这里是sqlite3与sqlserver

        <dependency>
            <groupId>org.xerial</groupId>
            <artifactId>sqlite-jdbc</artifactId>
            <version>3.36.0.3</version>
        </dependency>

        <dependency>
            <groupId>com.microsoft.sqlserver</groupId>
            <artifactId>mssql-jdbc</artifactId>
            <version>10.2.3.jre8</version>
        </dependency>

         <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
             <version>3.5.1</version>
        </dependency>

        <!-- 动态数据源 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>

    <!-- 阿里数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.16</version>
        </dependency>

在ruoyi-admin的application-druid.yml的配置

# 数据源配置
spring:
  autoconfigure:
    # 排除 Druid 自动配置
    exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure
  datasource:
    # 指定使用 Druid 数据源
    type: com.alibaba.druid.pool.DruidDataSource
    dynamic:
      #设置默认的数据源或者数据源组,默认值即为 master
      primary: master
      datasource:
        # 主库数据源
        master:
          url: jdbc:sqlite:sql/aaa.db
          driver-class-name: org.sqlite.JDBC
        # 从库数据源
        slave:
          driverClassName: com.microsoft.sqlserver.jdbc.SQLServerDriver
          url: jdbc:sqlserver://127.0.0.1:1433;databaseName=test;encrypt=false
          username: sa
          password: aaaaa
      druid:
        # 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
        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/*
          login-username: aaa
          login-password: aaaa
        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

在ruoyi-framework的中修改DruidProperties类与DruidConfig类

package com.ruoyi.framework.config.properties;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

/**
 * druid 配置属性
 *
 * @author ruoyi
 */
@Data
@Configuration
@ConfigurationProperties(prefix = "spring.datasource.dynamic.druid")
public class DruidProperties {

    private int initialSize;

    private int minIdle;

    private int maxActive;

    private int maxWait;

    private int connectTimeout;

    private int socketTimeout;

    private int timeBetweenEvictionRunsMillis;

    private int minEvictableIdleTimeMillis;

    private int maxEvictableIdleTimeMillis;

    private String validationQuery;

    private boolean testWhileIdle;

    private boolean testOnBorrow;

    private boolean testOnReturn;

    private StatViewServlet statViewServlet = new StatViewServlet();

    @Data
    public static class StatViewServlet {

        private String urlPattern;
        private String loginUsername;
        private String loginPassword;
    }


}

package com.ruoyi.framework.config;

import com.alibaba.druid.support.http.StatViewServlet;
import com.ruoyi.framework.config.properties.DruidProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.*;


/**
 * druid 配置多数据源
 *
 * @author ruoyi
 */
@Configuration
public class DruidConfig {

    @Autowired
    private DruidProperties druidProperties;


    /**
     * 配置Druid 监控启动页面
     *
     * @return servletRegistrationBean
     */
    @Bean
    @ConditionalOnMissingBean
    public ServletRegistrationBean<Servlet> druidStartViewServlet() {
        DruidProperties.StatViewServlet statViewServlet = druidProperties.getStatViewServlet();
        ServletRegistrationBean<Servlet> servletRegistrationBean = new ServletRegistrationBean<>(new StatViewServlet(), statViewServlet.getUrlPattern());
        // 白名单
        //servletRegistrationBean.addInitParameter("allow", "127.0.0.1");
        // 黑名单
//        servletRegistrationBean.addInitParameter("deny", "");
        // 登录查看信息的账密，用于登录Druid监控后台
        servletRegistrationBean.addInitParameter("loginUsername", statViewServlet.getLoginUsername());
        servletRegistrationBean.addInitParameter("loginPassword", statViewServlet.getLoginPassword());
        // 是否能够重置数据
        servletRegistrationBean.addInitParameter("resetEnable", "true");
        return servletRegistrationBean;
    }
}