SpringBoot整合Jpa项目（含Jpa 原生sql语句介绍）

1、插入语句

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

2、更新语句

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

3、查询语句

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

4、删除语句

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

注意：
不加@Transactional有可能会抛javax.persistence.TransactionRequiredException:异常，我是在抛异常之后才加上的。

@Transactional、 @Query、@Modifying这三个注解都是需要的

nativeQuery = true代表使用原生sql

---

下面贴一下完整代码：

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;

/**
 * 计数器 数据库映射
 *
 * @author zhaohualuo
 * @date 2019/8/30
 **/
@Component
public interface CountMapper extends JpaRepository<Count, Integer> {
    /*
     * 我们在这里直接继承 JpaRepository
     * 这里面已经有很多现场的方法了
     * 这也是JPA的一大优点
     *
     * */
    @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;

/**
 * 生成不重复数字
 *
 * @author zhaohualuo
 * @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;

/**
 * 累加器实体类
 *
 * @author zhaohualuo
 * @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>

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