SpringBoot整合Jpa項目（含Jpa 原生sql語句介紹）

一、插入語句

@Transactional 
@Query(value = "insert into number_rule values(?1,?2)", nativeQuery = true)
@Modifying 
int insertRule(int nums,int rule);

二、更新語句

@Transactional
@Query(value = "update number_count set count = ?1", nativeQuery = true)
@Modifying
public void updateCount(int count);

三、查詢語句

@Transactional
@Query(value = "select count from number_count")
@Modifying
Count selectCount();

四、刪除語句

@Transactional
@Modifying
@Query(value = "delete from number_count where count =?1",nativeQuery = true)
int deleteCount(int count);

注意：不加@Transactional有可能會拋javax.persistence.TransactionRequiredException:異常，我是在拋異常以後才加上的。

@Transactional、 @Query、@Modifying這三個註解都是須要的

nativeQuery = true表明使用原生sql

---

下面貼一下完整代碼：

package com.example.demo.mapper;

import com.example.demo.entity.Count;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

/**
 * 計數器 數據庫映射
 *
 * @author bws
 * @date 2019/8/30
 **/
@Component
public interface CountMapper extends JpaRepository<Count, Integer> {
   /*
     * 咱們在這裏直接繼承 JpaRepository
     * 這裏面已經有不少現場的方法了
     * 這也是JPA的一大優勢
     *
     * */
   @Transactional
   @Query(value = "update number_count set count = ?1", nativeQuery = true)
   @Modifying
   public void updateCount(int count);
}

---

package com.example.demo.controller;

import com.example.demo.entity.Count;
import com.example.demo.mapper.CountMapper;
import com.example.demo.service.DisorderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Calendar;
import java.util.List;
import java.util.Random;

/**
 * 生成不重複數字
 *
 * @author bws
 * @date 2019/8/30
 **/
@RestController
public class DisorderController {

    @Autowired CountMapper countMapper;

    @GetMapping("/list")
    public int findAll() {
        return countMapper.updateCount(1);
    }
}

---

package com.example.demo.entity;

import lombok.Data;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * 累加器實體類
 *
 * @author bws
 * @date 2019/8/30
 **/
@Data
@Entity
@Table(name = "number_count")
public class Count {

   @Id
   private int count;
}

---

application.yml

spring:
 devtools:
   restart:
     enabled: false
 datasource:
   driver-class-name: org.postgresql.Driver
   url: jdbc:postgresql://localhost:5432/xxx
   username: xxx
   password: xxx
 jpa:
   hibernate:
     ddl-auto: update
   show-sql: true
   database-platform: org.hibernate.dialect.PostgreSQLDialect
   properties:
     hibernate:
       temp:
         use_jdbc_metadata_defaults: false

---

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

   public static void main(String[] args) {
       SpringApplication.run(DemoApplication.class, args);
   }

}

---

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-parent</artifactId>
       <version>2.1.7.RELEASE</version>
       <relativePath/> <!-- lookup parent from repository -->
   </parent>
   <groupId>com.example</groupId>
   <artifactId>demo</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>demo</name>
   <description>Demo project for Spring Boot</description>

   <properties>
       <java.version>1.8</java.version>
   </properties>

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

       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-devtools</artifactId>
           <scope>runtime</scope>
           <optional>true</optional>
       </dependency>
       <dependency>
           <groupId>org.postgresql</groupId>
           <artifactId>postgresql</artifactId>
           <scope>runtime</scope>
       </dependency>
       <dependency>
           <groupId>org.projectlombok</groupId>
           <artifactId>lombok</artifactId>
           <optional>true</optional>
       </dependency>
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-test</artifactId>
           <scope>test</scope>
       </dependency>
   </dependencies>

   <build>
       <plugins>
           <plugin>
               <groupId>org.springframework.boot</groupId>
               <artifactId>spring-boot-maven-plugin</artifactId>
           </plugin>
       </plugins>
   </build>

</project>

---

啓動項目以後，訪問地址：

http://localhost:8080/list

— END—

關注做者微信公衆號 —《Java架構師聯盟》

瞭解更多java後端架構知識以及最新面試寶典

你點的每一個好看，我都認真當成了

看完本文記得給做者點贊+在看哦~~~你們的支持，是做者遠遠不斷出文的動力。

本文分享自微信公衆號 - Java架構師聯盟（msbxq2019）。
若有侵權，請聯繫 support@oschina.cn 刪除。
本文參與「OSC源創計劃」，歡迎正在閱讀的你也加入，一塊兒分享。