#一、 配置数据源:

<!-- 数据库 --> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId> 
</dependency>
<dependency>
<groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId> 
<scope>runtime</scope>
</dependency>

二、Jpa 配置

JPA

spring.jpa.hibernate.ddl-auto= update #显示 sql 语句 
spring.jpa.show-sql=true

三、 实体类

        @Entity
        public class RoncooUserLog {
         @Id
         @GeneratedValue
         private Integer id;
         @Column
         private Date createTime;
         @Column
         private String userName;
         @Column
         private String userIp;
         public Integer getId() {
              return id;
}

         public void setId(Integer id) {
              this.id = id;
}
         public Date getCreateTime() {
              return createTime;
}
         public void setCreateTime(Date createTime) {
              this.createTime = createTime;
}
         public String getUserName() {
              return userName;
}
         public void setUserName(String userName) {
              this.userName = userName;
}
         public String getUserIp() {
              return userIp;
}
         public void setUserIp(String userIp) {
              this.userIp = userIp;
}
         @Override
         public String toString() {
return "RoncooUserLog [id=" + id + ", createTime=" + createTime + ", userName=" + userName + ", userIp=" + userIp + "]";
} }

四、定义接口(继承 JpaRepository)

public interface RoncooUserLogDao extends JpaRepository<RoncooUserLog, Integer>{ }

五、 测试

@Autowired
private RoncooUserLogDao roncooUserLogDao;

@Test
public void insert() {
  RoncooUserLog entity = new RoncooUserLog(); entity.setUserName("无境"); 
entity.setUserIp("192.168.0.1"); entity.setCreateTime(new Date()); roncooUserLogDao.save(entity);
}
@Test
public void delete() {
    roncooUserLogDao.delete(1);
 }
 @Test
public void update() {
  RoncooUserLog entity = new RoncooUserLog();
  entity.setId(2);
  entity.setUserName("无境 2");  
  entity.setUserIp("192.168.0.1"); 
  entity.setCreateTime(new Date()); 
  roncooUserLogDao.save(entity);
}
@Test
public void select() {
     RoncooUserLog result = roncooUserLogDao.findOne(1);
     System.out.println(result);
}

六、 扩展进行自定义的查询

1. 使用内置的关键词查询
   http://docs.spring.io/spring-data/jpa/docs/1.10.2.RELEASE/reference/html/
2. 使用自定义语句查询
   各种语法,具体查看
   http://docs.spring.io/spring-data/jpa/docs/1.10.2.RELEASE/reference/html/
   这个优先级比上面的高

@Query(value = "select u from RoncooUserLog u where u.userName=?1")

测试

public void select2() { List<RoncooUserLog> result =
roncooUserLogDao.findByUserName("无境"); System.out.println(result);
}
@Test
public void select3() { List<RoncooUserLog> result =
roncooUserLogDao.findByUserNameAndUserIp("无境", "192.168.0.1");
System.out.println(result); }
// 分页 @Test
public void queryForPage() {
Pageable pageable = new PageRequest(0, 20, new Sort(new
Order(Direction.DESC, "id"))); 
Page<RoncooUserLog> result =
roncooUserLogDao.findByUserName("无境", pageable); 
System.out.println(result.getContent());
}