一、添加依赖：

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hsqldb</groupId>
            <artifactId>hsqldb</artifactId>
        </dependency>

二、注入JdbcTemplate进行数据库操作（或通过MyBatis)

package cn.edu.tju.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class DemoController {
    @Autowired
    private JdbcTemplate jdbcTemplate;


    @RequestMapping("/set")
    public String set(){
        jdbcTemplate.execute("create table user_table(x int,y int)");
        jdbcTemplate.execute("insert into user_table values(6,88)");
        return "set successfully";
    }



    @RequestMapping("/get")
    public String get(){
        Integer integer = jdbcTemplate.queryForObject("select y from user_table where x=? limit 1", new Object[]{6}, Integer.class);
        return String.valueOf(integer);
    }
}