Mybatis怎么连接数据库(mybatis,数据库,开发技术)

从零开始Mybatis连接数据库

创建Maven文件

File-->new-->project-->maven,点击next

配置

在出现的pom.xml文件中<project>标签之间加入以下内容

<!--打包方式--><packaging>jar</packaging><dependencies><!--加载Mybatis核心--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.7</version></dependency><!--Junit测试--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><!--mysql驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.3</version></dependency></dependencies>

在src-->main-->resources下创建文件mybatis-config.xml

在该文件中加入以下内容:

<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEconfigurationPUBLIC"-//mybatis.org//DTDConfig3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><!--配置连接数据库环境--><environmentsdefault="development"><environmentid="development"><transactionManagertype="JDBC"/><dataSourcetype="POOLED"><propertyname="driver"value="com.mysql.jdbc.Driver"/><propertyname="url"value="jdbc:mysql://localhost:3306/test"/><propertyname="username"value="自己的用户名"/><propertyname="password"value="自己的密码"/></dataSource></environment></environments></configuration>

注意将username和password的value值改成自己的,且在自己的数据库中创建test库

创建实体类

在main的java下创建我们需要与表中对应的实体类,这里我们写user类

publicclassUser{//实体类//属性与表中的各项对应,加入相应的get,set方法intuserid;Stringusername;Stringuserpass;Stringusertel;intusercarad;publicUser(){}publicUser(intuserid,Stringusername,Stringuserpass,Stringusertel,intusercarad){this.userid=userid;this.username=username;this.userpass=userpass;this.usertel=usertel;this.usercarad=usercarad;}publicintgetUserid(){returnuserid;}publicvoidsetUserid(intuserid){this.userid=userid;}publicStringgetUsername(){returnusername;}publicvoidsetUsername(Stringusername){this.username=username;}publicStringgetUserpass(){returnuserpass;}publicvoidsetUserpass(Stringuserpass){this.userpass=userpass;}publicStringgetUsertel(){returnusertel;}publicvoidsetUsertel(Stringusertel){this.usertel=usertel;}publicintgetUsercarad(){returnusercarad;}publicvoidsetUsercarad(intusercarad){this.usercarad=usercarad;}}

创建com.mapper包,并在包下创建UserMapper接口

这里我们简单做一个添加内容示例

packagecom.mapper;publicinterfaceUserMapper{intinsertUser();//返回值为改变的行数}

创建UserMapper.xml映射文件

在resources文件夹下创建mapper文件夹(包)并在其中创建UserMapper.xml

并在其中加入以下内容,这里要保证两个一致

<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTDMapper3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><!--第一个一致,namespace对应UserMapper接口全类名--><mappernamespace="com.mapper.UserMapper"><!--第二个一致,id对应方法名intinsertUser();--><insertid="insertUser">insertintouservalues(null,"tom","1234","111",22)</insert></mapper>

在mybatis-config.xml下<configuration>标签中最下面加入

<!--引入映射文件--><mappers><mapperresource="mapper/UserMapper.xml"/></mappers>

创建测试类

创建Test类进行测试

importcom.mapper.UserMapper;importorg.apache.ibatis.io.Resources;importorg.apache.ibatis.session.SqlSession;importorg.apache.ibatis.session.SqlSessionFactory;importorg.apache.ibatis.session.SqlSessionFactoryBuilder;importjava.io.IOException;importjava.io.Reader;publicclassTest{publicstaticvoidmain(String[]args)throwsIOException{//获取配置文件Readerreader=Resources.getResourceAsReader("mybatis-config.xml");//获取SqlSessionFactoryBuilder获取SqlSessionFactory工厂SqlSessionFactoryBuildersqlSessionFactoryBuilder=newSqlSessionFactoryBuilder();//获取SqlSessionFactory工厂SqlSessionFactorysqlSessionFactory=sqlSessionFactoryBuilder.build(reader);//利用工厂获取sqlSessionSqlSessionsqlSession=sqlSessionFactory.openSession();//openSession()加入参数true,即可实现自动提交事务//利用sqlSession的方法获取接口的对象UserMapperuserMapper=sqlSession.getMapper(UserMapper.class);//调用接口方法,从而调用映射文件的sql语句intnum=userMapper.insertUser();//提交事务sqlSession.commit();System.out.println("改变行数"+num);}}

运行结果: