jpa学习笔记——2

了解了以下几个注解，暂时学习的jpa只是将注解注释到mysql中，类的字段与表的字段一一对应，表可以自动生成，数据也可以自动添加

@Entity

@Transient

@Temporal

@Table

@Id

@GeneratedValue

@Column

@Basic

直接上代码

package com.huawei.test;import java.util.Date;import javax.persistence.Basic;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.Table;import javax.persistence.Temporal;import javax.persistence.TemporalType;import javax.persistence.Transient;import javax.xml.crypto.Data;@Table(name="JPA_CUSTOMERS")@Entitypublic class Customer {private Integer id;private String lastName;private String email;private int age;private Date createTime;private Date birth;//生成主键的策略@GeneratedValue(strategy=GenerationType.AUTO)@Idpublic Integer getId() {return id;}public void setId(Integer id) {this.id = id;}@Column(name="LAST_NAME", length=50, nullable=false)public String getLastName() {return lastName;}public void setLastName(String lastName) {this.lastName = lastName;}//默认是加上的 ，默认映射成数据表的一列@Basicpublic String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}//指定时间的类型，datetime类型，精确到秒@Temporal(TemporalType.TIMESTAMP)public Date getCreateTime() {return createTime;}public void setCreateTime(Date createTime) {this.createTime = createTime;}//指定时间的类型，date类型，精确到秒@Temporal(TemporalType.DATE)public Date getBirth() {return birth;}public void setBirth(Date birth) {this.birth = birth;}// 工具方法，不需要映射为数据表的一列//不映射成数据表的一列@Transientpublic String getInfo() {return "lastName" + this.lastName + " email:" + this.email;}}