网站开发预算怎么算,手机网站开发例子,注册公司没有场地怎么办,微站图片Mybatis方式完成CRUD操作 文章目录 Mybatis方式完成CRUD操作1、java以Mybatis方式操作DB1.1、配置数据源-创建 resources/mybatis-config.xml1.2、创建java bean-Monster1.3、配置Mapper接口声明方法1.4、配置xxMapper#xff0c;完成SQL配置,实现CRUD操作1.5、Test测试 2、需…Mybatis方式完成CRUD操作 文章目录 Mybatis方式完成CRUD操作1、java以Mybatis方式操作DB1.1、配置数据源-创建 resources/mybatis-config.xml1.2、创建java bean-Monster1.3、配置Mapper接口声明方法1.4、配置xxMapper完成SQL配置,实现CRUD操作1.5、Test测试 2、需要的Utils工具类3、pom基础依赖4、数据库建表操作 Java开发在以前做数据库连接的时候通过JDBC来完成非常麻烦。 现在引入了MyBatis这个框架Mybatis是简化数据库操作的持久层框架。
使用Mybatis的好处
mybatis 可以将对数据表的操作(sql,方法)等等直接剥离写到 xml 配置文件实现和 java 代码的解耦MyBatis 在 java 和 sql 之间提供更灵活的映射
1、java以Mybatis方式操作DB 1.1、配置数据源-创建 resources/mybatis-config.xml ?xml version1.0 encodingUTF-8 ?
!DOCTYPE configurationPUBLIC -//mybatis.org//DTD Config 3.0//ENhttps://mybatis.org/dtd/mybatis-3-config.dtd
configuration!-- 配置mybatis自带的日志输出--settingssetting namelogImpl valueSTDOUT_LOGGING//settings!-- 配置类型别名--typeAliasestypeAlias typecom.linghu.entity.Monster aliasMonster//typeAliasesenvironments defaultdevelopmentenvironment iddevelopment!-- 配置事务管理器--transactionManager typeJDBC/!-- 配置数据源--dataSource typePOOLED!-- 配置驱动--property namedriver valuecom.mysql.jdbc.Driver/!-- 配置数据库的链接--property nameurlvaluejdbc:mysql://127.0.0.1:3306/mybatis?useSSLtrueamp;useUnicodetrueamp;characterEncodingUTF-8/!-- 数据库的用户名和密码--property nameusername valueroot/property namepassword value123456//dataSource/environment/environments!-- 这里设置我们需要管理的mapper.xml文件--!-- 可以通过快捷键copy这个地址--mappersmapper resourcecom/linghu/mapper/MonsterMapper.xml//mappers/configuration1.2、创建java bean-Monster
创建bean的时候要对照自己设计的数据库表字段进行设计要一一对应
package com.linghu.entity;import java.util.Date;/*** author 令狐荣豪* version 1.0* Monster类和monster表有对应关系,字段要对应* 体现oop*/
public class Monster {private Integer id;private Integer age;private String name;private String email;private Date birthday;private double salary;private Integer gender;public Monster() {}public Monster(Integer id, Integer age, String name, String email, Date birthday, double salary, Integer gender) {this.id id;this.age age;this.name name;this.email email;this.birthday birthday;this.salary salary;this.gender gender;}Overridepublic String toString() {return Monster{ id id , age age , name name \ , email email \ , birthday birthday , salary salary , gender gender };}public Integer getId() {return id;}public void setId(Integer id) {this.id id;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age age;}public String getName() {return name;}public void setName(String name) {this.name name;}public String getEmail() {return email;}public void setEmail(String email) {this.email email;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday birthday;}public double getSalary() {return salary;}public void setSalary(double salary) {this.salary salary;}public Integer getGender() {return gender;}public void setGender(Integer gender) {this.gender gender;}
}
1.3、配置Mapper接口声明方法
package com.linghu.mapper;import com.linghu.entity.Monster;import java.util.List;/*** author 令狐荣豪* version 1.0* 定义增删改查的接口方法*/
public interface MonsterMapper {
// 添加monsterpublic void addMonster(Monster monster);//根据id删除一个Monsterpublic void delMonster(Integer id);//修改 Monsterpublic void updateMonster(Monster monster);//查询-根据 idpublic Monster getMonsterById(Integer id);//查询所有的 Monsterpublic ListMonster findAllMonster();
}
1.4、配置xxMapper完成SQL配置,实现CRUD操作
Monstermapper.xml:
?xml version1.0 encodingUTF-8 ?
!DOCTYPE mapperPUBLIC -//mybatis.org//DTD Mapper 3.0//ENhttps://mybatis.org/dtd/mybatis-3-mapper.dtd
mapper namespacecom.linghu.mapper.MonsterMapper!-- select idselectBlog resultTypeBlog--
!-- select * from Blog where id #{id}--
!-- /select--
!-- private Integer id;private Integer age;private String name;private String email;private Date birthday;private double salary;private Integer gender;--insert idaddMonster parameterTypecom.linghu.entity.Monsterinsert into monster(age,birthday,email,gender,name,salary)
!-- values(10,null,linghuqq.com,1,kate,1000),修改成活数据--
!-- 下面的名称对应的Monster对象的属性名--values(#{age},#{birthday},#{email},#{gender},#{name},#{salary})/insertdelete iddelMonster parameterTypeIntegerdelete from monster where id#{id};/delete!-- 这里的入参类型最好不要简写--
!-- 配置类型别名后这里可以简写Monster--
!-- update idupdateMonster parameterTypecom.linghu.entity.Monster--update idupdateMonster parameterTypeMonsterupdate monster set age#{age},birthday#{birthday},email#{email},gender#{gender},name#{name},salary#{salary}where id#{id}/update!-- resultType是个别名--select idgetMonsterById parameterTypeInteger resultTypeMonsterselect * from monster where id#{id};/select!-- 查询全部结果--select idfindAllMonster resultTypeMonsterselect * from monster;/select/mapper1.5、Test测试
package com.linghu.mapper;import com.linghu.entity.Monster;
import com.linghu.util.MyBatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Before;
import org.junit.Test;import java.util.Date;
import java.util.List;/*** author 令狐荣豪* version 1.0*/
public class MonsterMapperTest {private SqlSession sqlSession;private MonsterMapper monsterMapper;Beforepublic void init(){//通过SqlSessionFactory获取一个SqlSession会话sqlSession MyBatisUtils.getSqlSession();//获取MonsterMapper接口对象该对象实现了MonsterMappermonsterMappersqlSession.getMapper(MonsterMapper.class);System.out.println(monsterMapper.getClass());}// Test
// public void t1(){
// System.out.println(t1()。。。);
// }Testpublic void addMonster(){for (int i0;i3;i){Monster monster new Monster();monster.setAge(10i);monster.setBirthday(new Date());monster.setEmail(lignhuqq.com);monster.setGender(1);monster.setName(松鼠精i);monster.setSalary(1000i*10);
// id不用设置monsterMapper.addMonster(monster);System.out.println(添加对象-monster);}//如果是增删改需要提交事务if (sqlSession!null){sqlSession.commit();sqlSession.close();}System.out.println(保存成功···);}Testpublic void delMonster(){monsterMapper.delMonster(2);//如果是增删改需要提交事务if (sqlSession!null){sqlSession.commit();sqlSession.close();}System.out.println(删除成功···);}Testpublic void updateMonster(){Monster monster new Monster();monster.setAge(200);monster.setBirthday(new Date());monster.setEmail(hspedusohu.com);monster.setGender(2);monster.setName(狐狸精);monster.setSalary(9234.89);monster.setId(4);monsterMapper.updateMonster(monster);if (sqlSession ! null) {sqlSession.commit();sqlSession.close();}System.out.println(修改 ok);}Testpublic void getMonsterById(){
// Monster monster new Monster();Monster monstermonsterMapper.getMonsterById(6);System.out.println(monstermonster);if (sqlSession ! null) {sqlSession.commit();sqlSession.close();}System.out.println(查询 ok);}Testpublic void findAllMonster(){ //查询全部结果ListMonster allMonster monsterMapper.findAllMonster();for (Monster monster :allMonster) {System.out.println(monster);}if (sqlSession ! null) {sqlSession.close();}System.out.println(查询 ok);}
}
2、需要的Utils工具类
工具类MyBatisUtils.java
package com.linghu.util;import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;import javax.annotation.Resource;
import java.io.IOException;
import java.io.InputStream;/*** author 令狐荣豪* version 1.0* 这是一个工具类可以得到Sqlsession会话这个会话提供了执行SQL命令的方法CRUD*/
public class MyBatisUtils {private static SqlSessionFactory sqlSessionFactory;static {//静态代码块-初始化sqlSessionFactory对象try {/*** 指定资源文件*/String resourcemybatis-config.xml;//指定资源文件流InputStream inputStream Resources.getResourceAsStream(resource);//获取SqlSession实例sqlSessionFactorynew SqlSessionFactoryBuilder().build(inputStream);} catch (IOException e) {e.printStackTrace();}}/*** 返回一个SQLSession会话这个会话提供了执行SQL命令的方法CRUD* return*/public static SqlSession getSqlSession(){return sqlSessionFactory.openSession();}
}
3、pom基础依赖
?xml version1.0 encodingUTF-8?
project xmlnshttp://maven.apache.org/POM/4.0.0xmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsdmodelVersion4.0.0/modelVersiongroupIdcom.linghu/groupIdartifactIdLinghu_Mybatis/artifactIdversion1.0-SNAPSHOT/versionpackagingpom/packagingmodules
!-- 这里可以看到父项目下有哪些子项目--modulemybatisqucikstart/module/modulespropertiesmaven.compiler.source8/maven.compiler.sourcemaven.compiler.target8/maven.compiler.targetproject.build.sourceEncodingUTF-8/project.build.sourceEncoding/properties!-- 导入依赖 --dependenciesdependencygroupIdmysql/groupIdartifactIdmysql-connector-java/artifactIdversion5.1.49/version/dependencydependencygroupIdorg.mybatis/groupIdartifactIdmybatis/artifactIdversion3.5.7/version/dependencydependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.12/version/dependency/dependencies!-- 配置resources--
!-- 配置目的将src/main/java目录和子目录和src/main/resources目录和子目录的
资源文件xml和properties在build项目时导出到对应的target目录下
--buildresourcesresourcedirectorysrc/main/java/directoryincludesinclude**/*.xml/include/includes/resourceresourcedirectorysrc/main/resources/directoryincludesinclude**/*.xml/includeinclude**/*.properties/include/includes/resource/resources/build/project4、数据库建表操作
CREATE DATABASE mybatis
CREATE TABLE monster (id INT NOT NULL AUTO_INCREMENT, age INT NOT NULL, birthday DATE DEFAULT NULL, email VARCHAR(255) NOT NULL , gender TINYINT NOT NULL, name VARCHAR(255) NOT NULL, salary DOUBLE NOT NULL,PRIMARY KEY (id)
) CHARSETutf8
