springboot---jdbcTemplate方法_springboot jdbctemplate 详细-优快云博客

本文链接：https://blog.youkuaiyun.com/qw160/article/details/116231611

本文介绍了如何使用Spring Boot的JdbcTemplate进行数据库查询，包括list、string和整型数据的获取，以及增删改查操作。通过实例展示了如何返回JSON格式数据并处理HTTP请求。同时涵盖了Controller层面的实现和配置细节。

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查询数据库返回列表（json）

  List<Map<String, Object>> list = jdbcTemplate.queryForList("select * from mldn");

        return list.get(6);

查询数据库返回一个list(相当于上面的list>get(1,2,3,…))

@Controller

public class lianjie {
    @Autowired
    JdbcTemplate jdbcTemplate;

    @ResponseBody
    @GetMapping("/jdbc")
    public List l() {
        List<Map<String, Object>> list = jdbcTemplate.queryForList("select * from jingxiao");

        return list;


    }
}

查询数据库返回字符串/整形。。。

  List<Map<String, Object>> list = jdbcTemplate.queryForList("select password1 from user where username1="+name);
        String s=jdbcTemplate.queryForObject("select password1 from user where username1="+name,String.class);

增删改查

见
https://blog.youkuaiyun.com/weixin_40001125/article/details/88538576
insert实例
迷惑：不知道需要配置application.pripertiers吗，懒得试了
应该application.yml可以代替

package aaa.j2ee2.controller;

import com.fasterxml.jackson.databind.util.JSONPObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

@Controller
public class SwitchProduct {

    @Autowired    // 自动注入，spring boot会帮我们实例化一个对象
    private JdbcTemplate jdbcTempl;
    @RequestMapping(value = "/updata")
    @ResponseBody

    public Object update(HttpServletRequest request){


       //     String name=request.getParameter("username");
         //   int id=Integer.parseInt(request.getParameter("userId"));
        String id=request.getParameter("userId");
        System.out.println(id);
            Map<String,Object> map= new HashMap<>();
          //  map.put("success",true);
         //   map.put("message","更新成功");
      //  System.out.println(name);

        String sql = "insert into j2ee2(temperature)  values("+id+")";


       jdbcTempl.execute(sql);


            return map;







    }
}

返回字符串实例

package aa.mysql428.controller;



import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;
import java.util.Map;
@Controller

public class lianjie1 {
    @Autowired
    JdbcTemplate jdbcTemplate;

    @ResponseBody
    @GetMapping("/lianjie1")
    //public Map<String, Object> map(@RequestParam("username") String name , @RequestParam("userpassword") String password) {
    public String map(@RequestParam("username") String name , @RequestParam("userpassword") String password) {

        List<Map<String, Object>> list = jdbcTemplate.queryForList("select password1 from user where username1="+name);
        String s=jdbcTemplate.queryForObject("select password1 from user where username1="+name,String.class);
        //修改数据库
       return s;



    }
}