Spring JPA

Spring JPA无需关心 数据库字段，项目启动会字段创建表，只会新增字段 不会删除
1 pom

	
	 org.springframework.boot
	 spring-boot-starter-data-jpa
	
  

2 entity

import java.util.Date;

import javax.persistence.*;

import org.springframework.format.annotation.DateTimeFormat;

@Entity
@Table(name="t_test")
@DynamicInsert//save忽略null
@DynamicUpdate//update忽略null
public class TestEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "t_id")
    private Long id;
    @Column(name = "t_name")
    private String name;
    @Column(name = "t_name1")
    private String name1;
    
    @Column(name = "t_time")
    @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss")
    private Date time=new Date();

	public String getName1() {
		return name1;
	}

	public void setName1(String name1) {
		this.name1 = name1;
	}

	public Long getId() {
        return id;
    }
 
    public void setId(Long id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }

	public Date getTime() {
		return time;
	}

	public void setTime(Date time) {
		this.time = time;
	}
    
}

3 TestJPA

import java.io.Serializable;

import org.springframework.data.jpa.repository.*;

import com.game.entity.TestEntity;

public interface TestJPA extends JpaRepository,JpaSpecificationExecutor,Serializable {

}

4自定义查询方法

//	@Query(value = "SELECT * FROM t_users_thp WHERE t_users_thp.t_user_id=?", nativeQuery = true) // nativeQuery = true表示使用sql自己的方言查询，想查什么查什么， 按照字段数据类型返回就行了
//	User findByUserId(String userId);
或者使用JPA提供的快捷查询

	//相对于名字相等查询（其他字段同理），参数为name 命名为驼峰命名 
	User findById(String Id);