MyBatis basis -CRUD

A, mybatis environment to build step　

Step 1: Create maven project
Step Two: Import coordinate
third step: write the necessary code for (the entity class and persistence layer interface)
Step Four: Write SqlMapConfig.xml
Step five: Write mapping configuration file
Step Six: Writing Test class

Second, write sqlMapConfig.xml

<?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">
<!-- 主配置文件 -->
<configuration>
    <!-- 配置环境 -->
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/eesy_mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>

    <!- <>by mappers<->Specifies the location mapping configuration file
    
        mapper resource="com/jzq/dao/UserDao.xml"/>
    </mappers>
</configuration>

 

Third, adding CRUD methods in the persistence layer (DAO) interface 

Package com.jzq.dao; 

Import com.jzq.domain.User; 

Import java.util.List; 

/ ** 
 * @author JZQ 
 * @Create 2019-08-24 PM 1:39 
 * / 
public  interface UserDao { 
    List < the User> findAll (); 

    / ** 
     * preservation method 
     * @param the User
      * / 
    void saveUser (the User the User); 

    / ** 
     * modify method 
     * @param the User
      * / 
    void updateUser (the User the User); 

    / ** 
     * delete method 
     * @param userId
     * / 
    Void deleteUser (Integer userId); 

    / ** 
     * Looking for a specified user id 
     * @param id 
     * @return 
     * / 
    the User FindUser (Integer id); 
    / ** 
     * Fuzzy query 
     * / 
    List <the User> findByLikeName (String username) ;
     / ** 
     * total number of queries the user 
     * / 
    int findTotal (); 
}

 

Fourth, the configuration in the user's mapping configuration file (Mapper) in

<?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="com.jzq.dao.UserDao">
    <select id="findAll" resultType="com.jzq.domain.User">
        SELECT * from user
    </select>
    <!-- 保存用户 -->
    <insert id="saveUser" parameterType="com.jzq.domain.User " after insertion configuration, acquiring insert data id<-!>
        -->
        <selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER">
            SELECT last_insert_id();
        </selectKey>
        INSERT INTO user(username,birthday,sex,address)VALUE (#{username},#{birthday},#{sex},#{address})
    </insert>
    <!-- 更新用户 -->
    <update id="updateUser" parameterType="com.jzq.domain.User">
        UPDATE user set username=#{username},sex=#{sex} WHERE id=#{id};
    </update>
    <!--Delete user -> 
    < the Delete id = "deleteUser" parameterType = "Integer" > 
        DELETE the FROM the User the WHERE id = # {uId} 
    </ the Delete > 
    <-! Query specifies the user id -> 
    < the SELECT id = "FindUser" the parameterType = "Integer" the resultType = "com.jzq.domain.User" > 
        the SELECT * from the WHERE ID User UID = # {} 
    </ SELECT > 
    <-! fuzzy search based on the name -> 
    < SELECT ID = "findByLikeName" parameterType="String" resultType="com.jzq.domain.User">
        SELECT * from user WHERE username like #{name}
    </select>
    <!-- 查询用户的总记录数 -->
    <select id="findTotal" resultType="int">
        SELECT COUNT(id) from user;
    </select>
</mapper>

 

Fifth, test class test CRUD methods

package com.jzq.test;


import com.jzq.dao.UserDao;
import com.jzq.domain.User;
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 org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.InputStream;
import java.util.Date;
import java.util.List;

/**
 * @author jzq
 * @Create 2019-08-24 PM 2:44 
 * the CRUD operations 
 * / 
public  class MyBatisTest {
     Private the InputStream in;
     Private the SqlSession SQLSESSION;
     Private a SqlSessionFactory Factory;
     Private UserDao userDao; 

    @Before // performed prior to performing the test method 
    public  void the init () throws Exception {
         // read the configuration file to generate an input stream of bytes 
        in Resources.getResourceAsStream = ( "the SqlMapConfig.xml" );
         // Get SqlSessionFactory 
        Factory = new new the SqlSessionFactoryBuilder () Build (in).;
        // Get the object SQLSession
        = SQLSESSION factory.openSession ();
         // Get the proxy object dao 
        userDao = sqlSession.getMapper (UserDao. class ); 
    } 

    @After // performed after the test method of performing 
    public  void the destroy () throws Exception {
         // release resources 
        SQLSESSION .commit (); 
        sqlSession.close (); 
        in.close (); 
    } 

    / ** 
     * test to Find 
     * 
     * @throws Exception
      * / 
    @Test 
    public  void testFindAll () throws Exception {

         // execute the query in all methods 
        List <the User> Users = userDao.findAll ();
         for (the User User: Users) { 
            System.out.println (User); 
        } 
        // release resources 

        sqlSession.close (); 
        in. Close (); 
    } 

    
    / ** 
     * save operation test 
     * / 
    @Test 
    public  void testSave () throws Exception { 
        the User User = new new the User (); 
        user.setUsername ( "mybaitis_save" ); 
        user.setBirthday ( new new a Date ()) ; 
        user.setSex ("Male" );); 
        User.setAddress ( "District Beijing non-station" );
         // execute preservation method 
        userDAO.saveUser (User); 
        sqlSession.commit (); 
    } 

    / ** 
     * save operation test 
     * / 
    @Test 
    public  void testFindInsertId () throws Exception { 
        the User User = new new the User (); 
        user.setUsername ( "INSERT mybaitis_last" ); 
        user.setBirthday ( new new a Date ()); 
        user.setSex ( "F" ); 
        user.setAddress ( "District Beijing station" 
        System.out.println ("Before executing the Save operation" + User);
         // execute preservation method 
        userDAO.saveUser (User); 
        System.out.println ( "save operation after performing" + User); 
    } 

    / ** 
     * test update 
     * / 
    @Test 
    public  void testUpdate () throws Exception { 
        the User User = new new the User (); 
        user.setId ( 50 ); 
        user.setUsername ( "mybaitis_update" ); 
        user.setSex ( "F" );
         // execute the query in all methods 
         userDao.updateUser (user);
    } 

    / * * 
     * test delete 
     * / 
    @Test 
    public  void TestDelete () throws Exception { 

        userDao.deleteUser ( 48 ); 
    } 

    / ** 
     * test for the specified operation 
     * / 
    @Test 
    public  void testFindOne () throws Exception { 

        the User User userDao.findUser = (50 ); 
        System.out.println (User); 
    } 

    / ** 
     * test operation fuzzy search 
     * / 
    @Test 
    public  void testFindLikeName () throws Exception { 

        List<User> users = userDao.findByLikeName ( " % Small%" );
        for (the User User: Users) { 
            System.out.println (User); 
        } 
    } 
    / ** 
     * Total number of test queries the user 
     * / 
    @Test 
    public  void testFindTotal () {
         int COUNT = userDao.findTotal (); 
        the System.out .println (COUNT); 
    } 
}