spring boot系列（五）spring boot 配置spring data jpa (查询方法)

接着上面spring boot系列（四）spring boot 配置spring data jpa 保存修改方法继续做查询的测试：

1 创建UserInfo实体类，代码和https://www.cnblogs.com/kxm87/p/9273555.html中的一样。

2 创建数据库操作类相当于dao层，主要创建一个接口UserRepository，继承JpaRepository接口即可。本代码中主要都是自定义方法。

使用findXX 或者countXX（这两个不用编写sql，jpa会自动生成）  或者@Query 编写JPQL语句 或者原生语句

package com.cfj.ceshi.jpa.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

import com.cfj.ceshi.jpa.domain.UserInfo;

public interface UserRepository extends JpaRepository<UserInfo, Integer> {

    List<UserInfo> findByUserNameNotNull();  //不为空

    List<UserInfo> findByUserNameIsNull();   //为空

    /**
     * 按照姓名=?查询
     * 最终转成sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name=?
     * @param name
     * @return
     */
    UserInfo findByUserName(String name);//用名字直接查询

    /**
     * 按照 name = ? and age = ? 查询
     * 最终转成sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name=? and userinfo0_.age=?
     * @param name
     * @param age
     * @return
     */
    UserInfo findByUserNameAndAge(String name,String age);//and

    /**
     * 按照 id between ? and ? 查询
     * 最终解析sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     * userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     * where userinfo0_.id between ? and ?
     * @param idStrat
     * @param idEnd
     * @return
     */
    List<UserInfo> findByIdBetween(Integer idStrat,Integer idEnd);

    /**
     * 按照年龄统计行数
     * 最终解析sql语句为：select count(userinfo0_.id) as col_0_0_ from user_info userinfo0_ where userinfo0_.age=?
     * @param age
     * @return
     */
    Integer countByAge(String age);

    /**
     * 目的是类似 user_name like '%dd%'这种查询  所以必须用Containing
     * 这样会把%%包含在里面  如果直接是like  则不包含%
     * @param name
     * @return
     */
    List<UserInfo> findByUserNameContaining(String name);

    /**
     * 按照username in ()
     * 最终解析sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name in (? , ?)

     * @return
     */
    List<UserInfo> findByUserNameIn(List<String> list);

    /**
     * 使用JPA sql查询  注意  1 对应userName 2 对应age  ？号中的数字和参数表中从左向右顺序一一对应
     * @param userName
     * @param age
     * @return
     */
    @Query(value = "select u from UserInfo u where u.userName=?1 and u.age = ?2")
    UserInfo getUserInfo(String userName,String age);

    /**
     * 使用JPA sql查询  注意  1 对应userName 2 对应age  ？号中的数字和参数表中从左向右顺序一一对应
     * 返回name
     * @param userName
     * @param age
     * @return
     */
    @Query(value = "select u.userName from UserInfo u where u.userName=?1 and u.age = ?2")
    String getUserInfoTwo(String userName,String age);

    /**
     * 使用原生sql查询
     * @param userName
     * @param age
     * @return
     */
    @Query(value = "select * from user_info u where u.user_name=?1 and u.age = ?2" ,nativeQuery = true)
    UserInfo getUserInfoThree(String userName,String age);

    /**
     * 用参数方式
     * @param userName
     * @param age
     * @return
     */
    @Query(value = "select u.userName from UserInfo u where u.userName=:name and u.age = :age")
    String getUserInfoFour(@Param("name")String userName,@Param("age")String age);

    /**
     * jpa sql
     * @param age
     * @param userName
     * @return
     */
    @Modifying
    @Query(value = "update UserInfo u set u.age = ?1 where u.userName = ?2")
    Integer updateUserInfo(String age,String userName);

    /**
     * 原生sql
     * @param age
     * @param userName
     * @return
     */
    @Modifying
    @Query(value = "update user_info set age = ?1 where user_name = ?2",nativeQuery = true)
    Integer updateUserInfoOne(String age,String userName);

    /**
     * 删除方法
     * @param userName
     * @return
     */
    @Modifying
    @Query(value = "delete from  UserInfo u where u.userName = ?1")
    Integer deleteUserInfo(String userName);

}

3 创建service接口和它的实现类，代码如下：

package com.cfj.ceshi.jpa.service;

import java.util.List;

import com.cfj.ceshi.jpa.domain.UserInfo;

public interface UserService {

    public Integer save(UserInfo user);

    public void delete(Integer id);

    List<UserInfo> findByUserNameNotNull();

    List<UserInfo> findByUserNameIsNull();

    UserInfo findByUserName(String name);//用名字直接查询

    UserInfo findByUserNameAndAge(String name,String age);//and

    List<UserInfo> findByUserIdBetween(Integer idStrat,Integer idEnd);

    Integer countByAge(String age);

    List<UserInfo> findByUserNameContaining(String name);

    List<UserInfo> findByUserNameIn(List<String> list);

    UserInfo getUserInfo(String userName,String age);

    String getUserInfoTwo(String userName,String age);

    UserInfo getUserInfoThree(String userName,String age);

    String getUserInfoFour(String userName,String age);

    Integer updateUserInfo(String age,String userName);

    Integer updateUserInfoOne(String age,String userName);

    Integer deleteUserInfo(String userName);

    UserInfo findOne(Integer id);

    List<UserInfo> findAll();

}

package com.cfj.ceshi.jpa.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.cfj.ceshi.jpa.domain.UserInfo;
import com.cfj.ceshi.jpa.repository.UserRepository;
import com.cfj.ceshi.jpa.service.UserService;

@Service
@Transactional
public class UserServiceImpl implements UserService{

    @Autowired
    private UserRepository userRepository;

    @Override
    public Integer save(UserInfo user) {
        return userRepository.save(user).getId();
    }

    @Override
    public void delete(Integer id) {
         userRepository.delete(id);
    }

    @Override
    public List<UserInfo> findByUserNameNotNull() {
        return userRepository.findByUserNameNotNull();
    }

    @Override
    public List<UserInfo> findByUserNameIsNull() {
        return userRepository.findByUserNameIsNull();
    }

    @Override
    public UserInfo findByUserName(String name) {
        return userRepository.findByUserName(name);
    }

    @Override
    public UserInfo findByUserNameAndAge(String name, String age) {
        return userRepository.findByUserNameAndAge(name, age);
    }

    @Override
    public List<UserInfo> findByUserIdBetween(Integer idStrat, Integer idEnd) {
        return userRepository.findByIdBetween(idStrat, idEnd);
    }

    @Override
    public Integer countByAge(String age) {
        return userRepository.countByAge(age);
    }

    @Override
    public List<UserInfo> findByUserNameContaining(String name) {
        return userRepository.findByUserNameContaining(name);
    }

    @Override
    public List<UserInfo> findByUserNameIn(List<String> list) {
        return userRepository.findByUserNameIn(list);
    }

    @Override
    public UserInfo getUserInfo(String userName, String age) {
        return userRepository.getUserInfo(userName, age);
    }

    @Override
    public String getUserInfoTwo(String userName, String age) {
        return userRepository.getUserInfoTwo(userName, age);
    }

    @Override
    public UserInfo getUserInfoThree(String userName, String age) {
        return userRepository.getUserInfoThree(userName, age);
    }

    @Override
    public String getUserInfoFour(String userName, String age) {
        return userRepository.getUserInfoFour(userName, age);
    }

    @Override
    public Integer updateUserInfo(String age, String userName) {
        return userRepository.updateUserInfo(age, userName);
    }

    @Override
    public Integer updateUserInfoOne(String age, String userName) {
        return userRepository.updateUserInfoOne(age, userName);
    }

    @Override
    public Integer deleteUserInfo(String userName) {
        return userRepository.deleteUserInfo(userName);
    }

    @Override
    public UserInfo findOne(Integer id) {
        return userRepository.findOne(id);
    }

    @Override
    public List<UserInfo> findAll() {
        return userRepository.findAll();
    }

}

有删除或者修改的时候 service层一定要加上事务控制@Transactional，否则就会报错:Executing an update/delete query; nested exception is javax.persistence.TransactionRequiredException: Executing an update/delete query

4 创建控制类（controller）在spring boot  里面用web包表示，代码如下：

package com.cfj.ceshi.jpa.web;

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

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

import com.cfj.ceshi.jpa.domain.UserInfo;
import com.cfj.ceshi.jpa.service.UserService;

@RestController
@RequestMapping("/userquery")
public class UserQueryWeb {

    @Autowired
    private UserService userService;

    @RequestMapping("/checknull")
    public String getUserInfoOne() {
        String result = "id集合:[";
        //List<UserInfo> list = userService.findByUserNameNotNull();

        List<UserInfo> list = userService.findByUserNameIsNull();

        for (int i = 0; i< list.size(); i++) {
            UserInfo u = new UserInfo();
            u = list.get(i);
            result += u.getId().toString()+",";
        }
        result = result+"]";
        return result;

    }

    /**
     * 按照姓名=?查询
     * 最终转成sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name=?
     * @param name
     * @return
     */
    @RequestMapping("/getByName")
    public String getUserInfoByName(String name) {
        return userService.findByUserName(name).toString();

    }

    /**
     * 按照 name = ? and age = ? 查询
     * 最终转成sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name=? and userinfo0_.age=?
     * @param name
     * @param age
     * @return
     */
    @RequestMapping("/getByNameAndAge")
    public String getUserInfoByName(String name,String age) {
        return userService.findByUserNameAndAge(name, age).toString();

    }

    /**
     * 按照 id between ? and ? 查询
     * 最终解析sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     * userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     * where userinfo0_.id between ? and ?
     * @param idStrat
     * @param idEnd
     * @return
     */
    @RequestMapping("/getByIdBetween")
    public String getUserInfoTwo(Integer idStrat, Integer idEnd) {

        String result = "id集合:[";
        List<UserInfo> list = userService.findByUserIdBetween(idStrat, idEnd);

        for (int i = 0; i< list.size(); i++) {
            UserInfo u = new UserInfo();
            u = list.get(i);
            result += u.getId().toString()+",";
        }
        result = result+"]";
        return result;

    }
    /**
     * 按照年龄统计行数
     * 最终解析sql语句为：select count(userinfo0_.id) as col_0_0_ from user_info userinfo0_ where userinfo0_.age=?
     * @param age
     * @return
     */
    @RequestMapping("/getByCount")
    public Integer getCount(String age) {
        return userService.countByAge(age);

    }

    /**
     * 目的是类似 user_name like '%dd%'这种查询  所以必须用Containing
     * 这样会把%%包含在里面  如果直接是like  则不包含%
     * @param name
     * @return
     */
    @RequestMapping("/getByUserNameLike")
    public String getUserNameLike(String name) {

        String result = "id集合:[";
        List<UserInfo> list = userService.findByUserNameContaining(name);

        for (int i = 0; i< list.size(); i++) {
            UserInfo u = new UserInfo();
            u = list.get(i);
            result += u.getId().toString()+",";
        }
        result = result+"]";
        return result;

    }

    /**
     * 按照username in ()
     * 最终解析sql语句为：select userinfo0_.id as id1_0_, userinfo0_.age as age2_0_,
     *  userinfo0_.user_name as user_nam3_0_ from user_info userinfo0_
     *  where userinfo0_.user_name in (? , ?)

     * @return
     */
    @RequestMapping("/getByUserNameIn")
    public String getUserNameIn() {

        String result = "id集合:[";
        List<String> arrylist = new ArrayList<String>();
        arrylist.add("w");
        arrylist.add("ww");
        List<UserInfo> list = userService.findByUserNameIn(arrylist);

        for (int i = 0; i< list.size(); i++) {
            UserInfo u = new UserInfo();
            u = list.get(i);
            result += u.getId().toString()+",";
        }
        result = result+"]";
        return result;

    }

    /*以下使用@Query查询*/

    //使用JPA sql查询  注意  1 对应userName 2 对应age  ？号中的数字和参数表中从左向右顺序一一对应
    @RequestMapping("/testquery")
    public String getUserNameByNameAndAge() {

        return userService.getUserInfo("rrr", "333").toString();

    }

    //使用JPA sql查询  注意  1 对应userName 2 对应age  ？号中的数字和参数表中从左向右顺序一一对应  返回name
    @RequestMapping("/testquerytwo")
    public String getUserNameByNameAndAgeTwo(String name,String age) {

        return userService.getUserInfoTwo(name, age);

    }

    // 使用原生sql查询
    @RequestMapping("/testquerythree")
    public String getUserNameByNameAndAgeThree() {

        return userService.getUserInfo("rrr", "333").toString();

    }

    //使用参数方式 @Param("name")
    @RequestMapping("/testqueryfour")
    public String getUserNameByNameAndAgeFour(String name,String age) {

        return userService.getUserInfoFour(name, age);

    }

    //jpa sql  更新
    @RequestMapping("/updateUserInfo")
    public String updateUserInfo(String age,String name) {

        return userService.updateUserInfo(age, name).toString();

    }

    //原生sql 更新
    @RequestMapping("/updateUserInfoOne")
    public String updateUserInfoOne(String age,String name) {

        return userService.updateUserInfoOne(age, name).toString();

    }
    //删除
    @RequestMapping("/deleteUserInfo")
    public String deleteUserInfo(String name) {

        return userService.deleteUserInfo(name).toString();

    }

    //按照id查询 使用spring data jpa接口中的findOne方法
    @RequestMapping("/getOne")
    public String getOne(Integer id) {
        return userService.findOne(id).toString();
    }

    //按照id查询 使用spring data jpa接口中的findAll方法
    @RequestMapping("/getAll")
    public String getAll() {
        String result = "id集合:[";
        List<UserInfo> list = userService.findAll();

        for (int i = 0; i< list.size(); i++) {
            UserInfo u = new UserInfo();
            u = list.get(i);
            result += u.getId().toString()+",";
        }
        result = result+"]";
        return result;
    }

}

5 使用postman工具测试

以上都是查询方法，所有用postman方法测试的时候，使用GET方式，然后选择URL栏旁边的Params设置传参，如下图：

本项目码云地址：

https://gitee.com/kaixinmao/jpa_lianxi/tree/master/jpa