筆記要點
出錯分析與總結

/**測試第16章的增,刪,改 的內容
 *  錯誤1: <insert id="addEmp" parameterType="com.bean.Employee">  ,注意選取資料型別是parameterType,不是Map
 *  錯誤2: 按順序查詢全部資料,但是delete清楚資料後, id自增變數不是從零開始的;所以自己的while迴圈不好!
 *  ---------
 *  1. mybatis 支援允許增刪改查,直接定義如下型別: Integer/long/boolean型別
 *  2. 手動提交即可, openSession.commit();
 *  3.
 
 
*/

工程組織

EmployeeMapper.xml   (加入 增,刪,改 的sql對映語句的內容)

<?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.dao.EmployeeMapper">
    <!--
     namespace: 名稱空間
    id: 唯一標識
    resultType:返回值型別
    #{id} : 從傳遞過來的引數中取出id值
    public Employee getEmpById(Integer id);
    
 
-->
    <select id="getEmpById" resultType="com.bean.Employee" databaseId="mysql">
        select * from tbl_employee where id = #{id}
    </select>

    <!--
        public void addEmp(Employee employee);
        parameterType : 引數型別,可以省略;
        mysql支援自增主鍵,自增主鍵的獲取:mybatis也是利用statement.getGeneratedKeys()
        呼叫方法: 在標籤中新增即可: useGeneratedKeys="true";
    
 
-->
    <insert id="addEmp" parameterType="com.bean.Employee"
        useGeneratedKeys="true" keyProperty="id">
        insert into tbl_employee(last_name,email,gender)
        values (#{lastName},#{email},#{gender})
    </insert>
    <!--public void updateEmp(Employee employee);-->
    <update id="updateEmp" >
          update tbl_employee
          set last_name=#{lastName},email=#{email},gender=#{gender}
          where id=#{id}
    </update>
    <!--public void deleteEmpById(Integer id);-->
    <delete id="deleteEmpById">
        delete from tbl_employee where id=#{id}
    </delete>
</mapper>

EmployeeMapper.java   [com.dao 下的]

package com.dao;
import com.bean.*;
    //介面式程式設計! namespace: 名稱空間,指定為介面名字;
public interface EmployeeMapper {
    public Employee getEmpById(Integer id);
            //新增返回值型別,表示mybatis的會話狀態是true或者false
    public boolean addEmp(Employee employee);
    public boolean updateEmp(Employee employee);
    public boolean deleteEmpById(Integer id);
}

class test_tp16  測試類  [com.test下的]

package com.test;
import com.bean.Employee;
import com.dao.EmployeeMapper;
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.Test;

import java.io.IOException;
import java.io.InputStream;

/**測試第16章的增,刪,改 的內容
 *  錯誤1: <insert id="addEmp" parameterType="com.bean.Employee">  ,注意選取資料型別是parameterType,不是Map
 *  錯誤2: 按順序查詢全部資料,但是delete清楚資料後, id自增變數不是從零開始的;所以自己的while迴圈不好!
 *  ---------
 *  1. mybatis 支援允許增刪改查,直接定義如下型別: Integer/long/boolean型別
 *  2. 手動提交即可, openSession.commit();
 *  3.
 */
public class test_tp16 {
    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream=Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }
    @Test
    public void test03() throws IOException{
        //預設是不自動提交資料的,需要我們自己手動提交
        SqlSession openSession = getSqlSessionFactory().openSession();

        try {
            EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
            //1-1 測試:增加一條記錄
         //  Employee employee1 = new Employee(null, "jerry", "[email protected]", "0");
       //     mapper.addEmp(employee1);
            //1-1-1 測試自增:增加一條記錄
              Employee employee1 = new Employee(null, "葫蘆娃", "葫蘆娃@163.com", "0");
              mapper.addEmp(employee1);
            //1-2 測試; 更新一號的名字為 jerry,性別為1
//            Employee employee = new Employee(1, "jerry", "[email protected]", "1");
//            mapper.updateEmp(employee);
            //1-3 測試刪除,刪除第二號的員工
         //   boolean b= mapper.deleteEmpById(2);
         //   System.out.println(b);
            //1-4 測試; 按順序查詢全部資料,
            Employee employee;
            int i=1;
            while ((employee = mapper.getEmpById(i))!=null){
                i++;
                System.out.println(employee);
            }
            //2.手動提交
            openSession.commit();
        } finally {
            openSession.close();
        }
    }
}