jpa的配置和简单使用

1、pom依赖

//引入依赖
<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${springboot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${springcloudalibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

        </dependencies>
    </dependencyManagement>

2application.yml

server:
  port: 8099
  servlet:
    context-path: /

spring:
  application:
    name: demo
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
  datasource:
    url: jdbc:mysql://自己的数据库?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTC
    username: 
    password: 
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update #第一次建表create，后面用update，要不让每次重启都会新建表
    show-sql: true

 标准的MVC实现

3、Dao层（实现JpaRepository接口）

package com.example.demo.dao;

import com.example.demo.dto.EnterpriseDto;
import com.example.demo.pojo.EnterpriseBase;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author Havery
 * @create 2021-12-06-16:57
 */
public interface EnterpriseDao extends JpaRepository<EnterpriseBase,String> {

    /**
     * 根据姓名模糊查询
     * @param name
     * @return
     */
prise_main  where D_CO_NAME like CONCAT('%',:name,'%')", nativeQuery = true)
    @Query(value = "select * from da_enterprise_main  where D_CO_NAME like %?1%", nativeQuery = true)
    public Page<EnterpriseBase> findEnterpriseBaseByName(@Param("name") String name, Pageable pageable);
    /**
     * 查询需要的所有信息
     */
    @Query(value= "select ID,D_CO_NAME,D_ESTABLISH_DATE,D_CREDIT_CODE,D_LEGAL_PERSON,D_MOBILE,d_enterprise_code from da_enterprise_main",nativeQuery=true)
    public List<EnterpriseDto> findNeed();
    /**
     * 根据ID查询信息
     */
    @Query(value= "select ID,D_CO_NAME,D_ESTABLISH_DATE,D_CREDIT_CODE,D_LEGAL_PERSON,D_MOBILE,d_enterprise_code from da_enterprise_main where ID=:ID",nativeQuery=true)
    public EnterpriseDto findNeedByID(@Param("ID") String ID);

}

4、直接放控制层代码（jpa自带很多方法可以直接使用，简单记录和学习）

package com.example.demo.controller;

import com.example.demo.dao.EnterpriseDao;
import com.example.demo.dto.EnterpriseDto;
import com.example.demo.pojo.EnterpriseBase;
import com.example.demo.service.EnterpriseService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.*;
import org.springframework.data.querydsl.QPageRequest;
import org.springframework.util.ObjectUtils;
import org.springframework.web.bind.annotation.*;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Havery
 * @create 2021-12-06-16:57
 */
@RestController
public class EnterpriseController {
    @Autowired
    EnterpriseDao enterpriseDao;

    @Autowired
    EnterpriseService enterpriseService;

    /**
     * 根据企业名称模糊查询
     */
    @RequestMapping("/dimFindEnterpriseBaseByName")
    public Page<EnterpriseBase> dimFindEnterpriseBaseByName( @RequestParam("name") String name,
                                                             @RequestParam("page") Integer page,
                                                             @RequestParam("size") Integer size
                                                            ){
        Page<EnterpriseBase> enterpriseBaseByName = enterpriseService.dimFindEnterpriseBaseByName(name, page,size);
        return enterpriseBaseByName;
    }

    /**
     * 返回所有企业信息
     */
    @RequestMapping("/AllQuery")
    @ResponseBody
    public List<EnterpriseBase> AllFindEnterprise(){
        List<EnterpriseBase> all = enterpriseDao.findAll();
        return all;
    }
    /**
     * 返回所有企业信息(分页)
     */
    @RequestMapping("/AllQueryEnterprise/{page}/{size}")
    @ResponseBody
    public Page<EnterpriseBase> AllQueryEnterprise(@PathVariable("page") Integer page,@PathVariable("size") Integer size){
        Pageable pageable=PageRequest.of(page-1,size);
        Page<EnterpriseBase> all = enterpriseDao.findAll(pageable);
        return all;
    }
    @RequestMapping("/updateInfo")
    public String updateEnterpriseInfo(EnterpriseBase enterpriseBase){
          EnterpriseBase update = enterpriseDao.save(enterpriseBase);
          if(update!=null){
              return "success";
          }else {
              return "error";
          }
    }
    /**
     * 根据id查询
     * @return
     */
    @RequestMapping("/queryFindById")
    public boolean queryFindById(String ID){
        return enterpriseDao.existsById(ID);
    }
    /**
     * 增加信息
     */
    @ResponseBody
    @RequestMapping("/AddInfo")
    public EnterpriseBase appEnterpriseInfo(EnterpriseBase enterpriseBase){
        EnterpriseBase saveEnterprise = enterpriseDao.save(enterpriseBase);
        return saveEnterprise;
    }
    /**
     * 根据id查找
     */
    @RequestMapping("/findNeedByID/{ID}")
        public EnterpriseDto findNeedByID(@PathVariable("ID") String ID){
        return enterpriseService.findNeedByID(ID);
    }
    /**
     * 根据id删除
     */
    @RequestMapping("/deleteByID")
    @ResponseBody
    public boolean deleteByID(@RequestBody List<EnterpriseBase> enterpriseBases){
        enterpriseDao.deleteInBatch(enterpriseBases);
        return true;
    }
}