1、springboot 启动类加入bean 如下
// DatabaseIdProvider元素主要是为了支持不同的数据库@Beanpublic DatabaseIdProvider getDatabaseIdProvider() { DatabaseIdProvider databaseIdProvider = new VendorDatabaseIdProvider(); Properties properties = new Properties(); properties.setProperty("Oracle", "oracle"); properties.setProperty("MySQL", "mysql"); databaseIdProvider.setProperties(properties); return databaseIdProvider;}

2、application.yml 配置
spring:
datasource:# 使用mysql
# driver-class-name: com.mysql.jdbc.Driver
# url: jdbc:mysql://localhost:3306/test?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
# username: root
# password: root#使用oracle
url: jdbc:oracle:thin:@//localhost:1521/orcl
username: system
password: system
driver-class-name: oracle.jdbc.driver.OracleDriver
3、部分pojo
@Data
@Accessors(chain = true)
public class Note {
private int userId;
private String userName;
private String userAge;
}
4、mapper 如下(注意oracle 语句的大小写,若小写请加“”引号)
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.sunyard.bigdata.dao.NoteMapper">
<select id="queryAll" resultType="com.sunyard.bigdata.pojo.Note" databaseId="oracle">
SELECT USER_ID,USER_NAME,USER_AGE FROM T_USER
</select>
<select id="queryAll" resultType="com.sunyard.bigdata.pojo.Note" databaseId="mysql">
SELECT user_id,user_name,user_age FROM t_user
</select>
</mapper>
5、表
mysql
DROP TABLE IF EXISTS `t_user`; CREATE TABLE `t_user` ( `user_id` int(11) NOT NULL AUTO_INCREMENT, `user_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL, `user_age` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL, PRIMARY KEY (`user_id`) USING BTREE ) ENGINE = InnoDB AUTO_INCREMENT = 3 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

oracle
CREATE TABLE "SYSTEM"."T_USER"
( "USER_ID" NUMBER(*,0),
"USER_NAME" VARCHAR2(20 BYTE),
"USER_AGE" VARCHAR2(20 BYTE)
) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SYSTEM" ;

6、controller测试
@Controller
@RequestMapping("/note")
public class NoteController {
@Autowired
NoteMapper noteMapper;
@RequestMapping("/queryall")
@ResponseBody
List<Note> queryAll() {
return noteMapper.queryAll();
}
}
7、l浏览器测试
切换oracle数据源

切换mysql数据源

源码地址:https://github.com/zhugaopo/springboot-2database
来源:https://www.cnblogs.com/godpo/p/12369708.html