MyBatis Study Notes First lecture

First step: Configure the MyBatis configuration first

<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE configuration Public "-//mybatis.org//dtd Config 3.0//en" "Http://mybatis.org/dtd/mybatis-3-config.dtd" > <configuration> <typeAliases> <typealias alias= "Users" type= "ORM. Users "/> </typeAliases> <environments default=" Development "> <environment id=" Development "> <transactionmanager type=" JDBC "/> <datasource type=" pooled "> <property n Ame= "Driver" value= "Com.mysql.jdbc.Driver"/> <property name= "url" value= "Jdbc:mysql://127.0.0.1:3306/myba Tis?characterencoding=utf-8 "/> <property name=" username "value=" root "/> <property name=        "Password" value= "123456"/> </dataSource> </environment> </environments> <mappers> <mapper resource= "Orm/users.xml"/> </mappers></configuration>

Step two: Create an Entity object

Package Orm;public class Users {private Integer id;private string username;private string password;private Integer age;pri vate integer sex;public Users (integer ID, string username, string password, integer age,integer sex) {super (); this.id = ID ; this.username = Username;this.password = Password;this.age = Age;this.sex = sex;} You must add a non-parametric construct public Users () {}//set and get omitted @overridepublic String toString () {//TODO auto-generated method Stubreturn super.tostring ();}}

Step Three: Configure a simple query parameter

<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE Mapper Public "-//mybatis.org//dtd mapper 3.0//en" "Http://mybatis.org/dtd/mybatis-3-mapper.dtd" >< Mapper Namespace= "ORM. Users ">    <select id=" Selectuserbyid "  parametertype=" int "resulttype=" orm. Users ">        select * from Users where id = #{id}    </select></mapper>

Fourth step: Test (Compact version)

String resstring= "Configuration.xml";  Reader reader = Resources.getresourceasreader (resstring); Sqlsessionfactory sessionfactory = new Sqlsessionfactorybuilder (). build (reader); sqlsession session =  sessionfactory.opensession (); String statement = "ORM. Users.selectuserbyid "; Users users = (ORM. Users) Session.selectone (statement,2); System.out.println (Users.getusername ());

Fourth Step: Test (complete version)

public class Test {    private static sqlsessionfactory sqlsessionfactory;    private static reader reader;     static{        try{            Reader    = Resources.getresourceasreader ("Configuration.xml");            Sqlsessionfactory = new Sqlsessionfactorybuilder (). build (reader);        catch (Exception e) {            e.printstacktrace ();        }    }    public static Sqlsessionfactory getsession () {        return sqlsessionfactory;    }        public static void Main (string[] args) {        sqlsession session = Sqlsessionfactory.opensession ();        Try {        Users users = (users) session.selectone ("ORM. Users.selectuserbyid ", 2);        System.out.println (users);        } finally {        session.close ();}}    }

　　

MyBatis Study Notes First lecture