Mybaits入门

mybaits入门

一、先配置主配置文件xml（mybaits-config.xml）
导入mybatis包（这里会链接mysql数据库所以mysql包也得导入）
注意：这里创建的实例是java项目

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <!-- 约束 -->
 3 <!doctype configuration
 4   public "-//mybatis.org//dtd config 3.0//en"
 5   "http://mybatis.org/dtd/mybatis-3-config.dtd">
 6 
 7   <configuration>
 8       <!-- 导入properties 文件 -->
 9       <properties resource="db.properties"></properties>
10       
11         <!--环境配置(链接数据库) -->
12       <environments default="development">
13            <environment id="development">
14                <!-- 事务控制 -->
15                <transactionmanager type="jdbc" />
16                <!-- 数据源 -->
17                <datasource type="pooled">
18                    <property name="driver" value="${driver}"/>
19                    <property name="url" value="${url}"/>
20                    <property name="username" value="${username}"/>
21                    <property name="password" value="${password}"/>
22                </datasource>
23            </environment>
24       </environments>
25       
26       <!-- 引入映射文件 -->
27       
28       <mappers>
29           <mapper resource="mybatis-student.xml"/>
30       </mappers>
31   </configuration>

二、建立properties联系数据源

1 driver=com.mysql.jdbc.driver
2 url=jdbc:mysql:///bj
3 username=root
4 password=123456

三、配置映射文件（mybatis-student.xml）(增删改查在这里进行)

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <!doctype mapper
 3   public "-//mybatis.org//dtd mapper 3.0//en"
 4   "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 5   
 6 <mapper namespace="student">
 7     <insert id="addstudent" parametertype="org.laogao.pojo.student">
 8         insert into student values(#{id},#{name},#{age},#{sex});
 9     </insert>
10     
11     <delete id="delete" parametertype="org.laogao.pojo.student">
12         delete from  student where id=#{id}
13     </delete>
14   
15   <update id="updatestudent" parametertype="org.laogao.pojo.student">
16       update student set name=#{name},age=#{age},sex=#{sex} where id=#{id}
17   
18   
19   </update>
20   
21   <select id="showstudent"  resulttype="org.laogao.pojo.student">
22   
23       select * from student 
24   </select>
25   
26   <select id="showstudentone" resulttype="org.laogao.pojo.student" parametertype="org.laogao.pojo.student">
27   
28   select * from student where id=#{id}
29   
30   </select>
31 </mapper>

四、建立测试类（这种公司里基本不用，但利于新手理解，了解即可）
常用类型请看mybaits进阶

public class testmybatis  {
    @test
 //写法用的是junit
    public void addstudent() throws ioexception{
        //解析主配置文件成一个输入流
        inputstream stream = resources.getresourceasstream("mybaits-config.xml");
        //sqlsession工厂
        //通过sqlsessionfactorybuilder.build(stream)构建实例获得sqlsessionfactory
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder().build(stream);
        
        //生成sql
        sqlsession session = sqlsessionfactory.opensession();
        //写一条数据
        student student = new student(0, "hp", "12", "nv");
        //增加
        session.insert("student.addstudent", student);
        session.commit();
    }
 
 
    @test
    public void deletestudentbyid() throws exception{
        //解析主配置文件成一个输入流
        inputstream stream = resources.getresourceasstream("mybaits-config.xml");
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder().build(stream);
        
        sqlsession session = sqlsessionfactory.opensession();
        
        session.delete("student.delete", 22);
        session.commit();
    }
    @test
    public void updatestudentnyid() throws exception{
        inputstream stream = resources.getresourceasstream("mybaits-config.xml");
        
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder().build(stream);
        
        sqlsession session = sqlsessionfactory.opensession();
        
        student student = new student(15, "sb", "20", "s");
        session.update("student.updatestudent", student);
        session.commit();
    }
    
    @test
    public void showstudent() throws exception{
        inputstream stream = resources.getresourceasstream("mybaits-config.xml");
        
        sqlsessionfactory sqlsessionfactory = new sqlsessionfactorybuilder().build(stream);
        
        sqlsession session = sqlsessionfactory.opensession();
        list<student> studentlist=session.selectlist("student.showstudent",null);
        for (student student : studentlist) {
            system.out.println(student.tostring());
            
        }
        
    }
    
    
    
    @test
    public void showstudentone() throws exception{
        inputstream stream = resources.getresourceasstream("mybaits-config.xml");
        
        sqlsessionfactory  sqlsessionfactory= new sqlsessionfactorybuilder().build(stream);
        
        sqlsession session = sqlsessionfactory.opensession();
        
        
        object student = session.selectone("student.showstudentone", 15);
        system.out.println(student.tostring());
    }
}