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Hibernate常用的Java数据类型映射到mysql和Oracle

發(fā)布時間：2025/3/15 数据库 34 豆豆

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　　研究了常用的Java基本數(shù)據(jù)類型在mysql和oracle數(shù)據(jù)庫的映射類型。這里使用的是包裝類型做研究，一般在hibernate聲明的時候最好不要用基本類型，因為數(shù)據(jù)庫中的null空數(shù)據(jù)有可能映射為基本類型的時候會報錯，但是映射到包裝類型的時候值為null，不會報錯。

1.常見數(shù)據(jù)類型在Mysql數(shù)據(jù)庫的映射

實體:

package cn.qlq.domain;import java.sql.Time; import java.util.Date;public class TestType {private Long id;private Integer age;private Character sex;private Boolean isPerson;private Date birth;private Time birthTime;private String name;public Long getId() {return id;}public void setId(Long id) {this.id = id;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Character getSex() {return sex;}public void setSex(Character sex) {this.sex = sex;}public Boolean getIsPerson() {return isPerson;}public void setIsPerson(Boolean isPerson) {this.isPerson = isPerson;}public Date getBirth() {return birth;}public void setBirth(Date birth) {this.birth = birth;}public Time getBirthTime() {return birthTime;}public void setBirthTime(Time birthTime) {this.birthTime = birthTime;}public String getName() {return name;}public void setName(String name) {this.name = name;}@Overridepublic String toString() {return "TestType [id=" + id + ", age=" + age + ", sex=" + sex + ", isPerson=" + isPerson + ", birth=" + birth+ ", birthTime=" + birthTime + ", name=" + name + "]";}}

xml:

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.qlq.domain" ><class name="TestType" table="testtype" ><id name="id" ><generator class="native"></generator></id><property name="age"/><property name="sex"/><property name="isPerson"/><property name="birth"/><property name="birthTime"/><property name="name"/></class> </hibernate-mapping>

Mysql映射的類型:

結(jié)果:

Long------------------------------bigint

Integer-----------------------? ? int

Character---------------------? char

Bolean---------------------------bit

java.util.Date;--------------datetime

java.sql.Time;------------------time

String----------------------------varchar(255)

插入數(shù)據(jù):

public static void main(String[] args) {//3.3以及之前的版本構(gòu)建會話工廠對象 // SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();//5.0之后獲取SessionFactory//創(chuàng)建服務(wù)注冊對象ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();//創(chuàng)建會話工廠對象SessionFactory sessionFactory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory();//獲取session對象Session session = sessionFactory.openSession();//開啟事務(wù)Transaction tx = session.beginTransaction();//保存對象TestType t1 = new TestType();TestType t2 = new TestType();t1.setAge(22);t2.setAge(23);t1.setName("zhangsan");t2.setName("zhangsanhaha");t1.setSex('1');t2.setSex('2');t1.setBirth(new Date());t2.setBirth(new Date());t1.setIsPerson(true);t2.setIsPerson(false);session.save(t1);session.save(t2);tx.commit();//關(guān)閉流 session.close();sessionFactory.close();}

結(jié)果:

mysql> select * from testtype; +----+------+------+----------+---------------------+-----------+--------------+ | id | age | sex | isPerson | birth | birthTime | name | +----+------+------+----------+---------------------+-----------+--------------+ | 1 | 22 | 1 | | 2018-08-10 22:39:19 | NULL | zhangsan | | 2 | 23 | 2 | | 2018-08-10 22:39:19 | NULL | zhangsanhaha | +----+------+------+----------+---------------------+-----------+--------------+ 2 rows in set (0.00 sec)

查詢

(1)基本查詢:

@Test// HQL查詢所有數(shù)據(jù)public void fun1() {// 1 獲得sessionSession session = HibernateUtil.openSession();// 2.書寫HQL語句 // String hql = "from cn.qlq.domain.Customer";// from 類名全路徑String hql = "from TestType";// 如果整個項目中只有這一個類名可以直接寫名字// 3.根據(jù)hql創(chuàng)建查詢對象Query query = session.createQuery(hql);// 4.根據(jù)查詢對象獲取查詢結(jié)果List<TestType> list = query.list();System.out.println(list);}

結(jié)果:

[TestType [id=1, age=22, sex=1, isPerson=true, birth=2018-08-10 22:39:19.0, birthTime=null, name=zhangsan], TestType [id=2, age=23, sex=2, isPerson=false, birth=2018-08-10 22:39:19.0, birthTime=null, name=zhangsanhaha]]

(2)條件查詢:----針對上面的類型進行條件查詢

@Test// HQL查詢所有數(shù)據(jù)public void fun1() {// 1 獲得sessionSession session = HibernateUtil.openSession();// 2.書寫HQL語句 // String hql = "from cn.qlq.domain.Customer";// from 類名全路徑String hql = "from TestType where age = 22 and sex = 1 and isPerson = true and name = 'zhangsan' and birth like '2018-08-10%'";// 如果整個項目中只有這一個類名可以直接寫名字// 3.根據(jù)hql創(chuàng)建查詢對象Query query = session.createQuery(hql);// 4.根據(jù)查詢對象獲取查詢結(jié)果List<TestType> list = query.list();System.out.println(list);}

結(jié)果:

selecttesttype0_.id as id1_0_,testtype0_.age as age2_0_,testtype0_.sex as sex3_0_,testtype0_.isPerson as isPerson4_0_,testtype0_.birth as birth5_0_,testtype0_.birthTime as birthTim6_0_,testtype0_.name as name7_0_ fromtesttype testtype0_ wheretesttype0_.age=22 and testtype0_.sex=1 and testtype0_.isPerson=1 and testtype0_.name='zhangsan' and (testtype0_.birth like '2018-08-10%') [TestType [id=1, age=22, sex=1, isPerson=true, birth=2018-08-10 22:39:19.0, birthTime=null, name=zhangsan]]

補充:Mysql的boolean類型也可以用true_false表示，數(shù)據(jù)類型會變?yōu)閏har(1)，存的是T和F:

2.常見數(shù)據(jù)類型在Oracle數(shù)據(jù)庫的映射

Oracle映射上面直接映射會報錯，解決辦法:? 將boolean映射為hibernate的true_false? (原理都是在數(shù)據(jù)庫存T或者F，F為false，T為true)

第一種:? ?boolean映射為yes_no

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="cn.qlq.domain" ><class name="TestType" table="testtype" ><id name="id" ><generator class="native"></generator></id><property name="age"/><property name="sex"/> <property name="isPerson" type="true_false"/><property name="birth"/><property name="birthTime"/><property name="name"/></class> </hibernate-mapping>

結(jié)果:

總結(jié):

Long------------------------------number

Integer-----------------------? ? number

Character---------------------? char

Bolean---------------------------char

java.util.Date;--------------date

java.sql.Time;------------------date

String----------------------------varchar(255)

添加數(shù)據(jù):

package cn.qlq.util;import java.util.Date;import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.boot.MetadataSources; import org.hibernate.boot.registry.StandardServiceRegistryBuilder; import org.hibernate.service.ServiceRegistry;import cn.qlq.domain.TestType;public class TestSave {public static void main(String[] args) {//3.3以及之前的版本構(gòu)建會話工廠對象 // SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();//5.0之后獲取SessionFactory//創(chuàng)建服務(wù)注冊對象ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure().build();//創(chuàng)建會話工廠對象SessionFactory sessionFactory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory();//獲取session對象Session session = sessionFactory.openSession();//開啟事務(wù)Transaction tx = session.beginTransaction();//保存對象TestType t1 = new TestType();TestType t2 = new TestType();t1.setAge(22);t2.setAge(23);t1.setName("zhangsan");t2.setName("zhangsanhaha");t1.setSex('1');t2.setSex('2');t1.setBirth(new Date());t2.setBirth(new Date());t1.setIsPerson(true);t2.setIsPerson(false);session.save(t1);session.save(t2);tx.commit();//關(guān)閉流 session.close();sessionFactory.close();} }

結(jié)果:

查詢所有:

@Test// HQL查詢所有數(shù)據(jù)public void fun1() {// 1 獲得sessionSession session = HibernateUtil.openSession();// 2.書寫HQL語句String hql = "from cn.qlq.domain.TestType";// from 類名全路徑// 3.根據(jù)hql創(chuàng)建查詢對象Query query = session.createQuery(hql);// 4.根據(jù)查詢對象獲取查詢結(jié)果List<TestType> list = query.list();System.out.println(list);}

結(jié)果:

Hibernate: selecttesttype0_.id as id1_0_,testtype0_.age as age2_0_,testtype0_.sex as sex3_0_,testtype0_.isPerson as isPerson4_0_,testtype0_.birth as birth5_0_,testtype0_.birthTime as birthTim6_0_,testtype0_.name as name7_0_ fromtesttype testtype0_ [TestType [id=15, age=22, sex=1, isPerson=true, birth=2018-08-10 23:19:33.0, birthTime=null, name=zhangsan], TestType [id=16, age=23, sex=2, isPerson=false, birth=2018-08-10 23:19:33.0, birthTime=null, name=zhangsanhaha]]

?按上面的條件查詢:

@Test// HQL查詢所有數(shù)據(jù)public void fun1() {// 1 獲得sessionSession session = HibernateUtil.openSession();// 2.書寫HQL語句String hql = "from TestType where age = 22 and sex = 1 and isPerson = true and name = 'zhangsan'";// 如果整個項目中只有這一個類名可以直接寫名字// 3.根據(jù)hql創(chuàng)建查詢對象Query query = session.createQuery(hql);// 4.根據(jù)查詢對象獲取查詢結(jié)果List<TestType> list = query.list();System.out.println(list);}

結(jié)果:? (日期不能直接like了)

Hibernate: selecttesttype0_.id as id1_0_,testtype0_.age as age2_0_,testtype0_.sex as sex3_0_,testtype0_.isPerson as isPerson4_0_,testtype0_.birth as birth5_0_,testtype0_.birthTime as birthTim6_0_,testtype0_.name as name7_0_ fromtesttype testtype0_ wheretesttype0_.age=22 and testtype0_.sex=1 and testtype0_.isPerson='T' and testtype0_.name='zhangsan' [TestType [id=15, age=22, sex=1, isPerson=true, birth=2018-08-10 23:19:33.0, birthTime=null, name=zhangsan]]

?總結(jié):?

　　對于mysql和oracle的boolean的通用類型就是true_false，hibernate會將字段類型設(shè)置為char(1)，然后true的時候存T，false的時候存F。

轉(zhuǎn)載于:https://www.cnblogs.com/qlqwjy/p/9457988.html

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