MyBatis.3.CRUD

<?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="org.mybatis.example.dao.DeptMapper">
  <select id="selectOne" parameterType="int"
    resultType="org.mybatis.example.dao.Dept">
      select * from dept where deptno=#{id}
  </select>
  <insert id="insertDept" parameterType="org.mybatis.example.dao.Dept"
  useGeneratedKeys="true" keyProperty="dept">
    insert into dept(dname,loc)
    values(
         #{dname,jdbcType=VARCHAR},
         #{loc,jdbcType=VARCHAR})
  </insert> 
  <update id="updateDept" parameterType="org.mybatis.example.dao.Dept">
    update dept set dname=#{dname},loc=#{loc}
          where deptno=#{deptno}
  </update>
  <delete id="deleteDept" parameterType="java.lang.Integer">
    delete from dept where deptno=#{id}
  </delete>
</mapper>

package org.mybatis.example.dao;

public interface DeptMapper {
  public Dept selectOne(int id);
  public int insertDept(Dept dept);
  public int updateDept(Dept dept);
  public int deleteDept(int id);
}

import java.io.IOException;
import java.io.Reader;

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.mybatis.example.dao.Dept;
import org.mybatis.example.dao.DeptMapper;


public class Test2 {
  public static void main(String[] args) throws IOException {
    String resource="mybatisConfig.xml";
    Reader reader=Resources.getResourceAsReader(resource);
    SqlSessionFactory sqlMapper=new SqlSessionFactoryBuilder().build(reader);

    SqlSession session=sqlMapper.openSession();

    try {
      DeptMapper mapper=session.getMapper(DeptMapper.class);
      //1.查询
//      Dept dept=mapper.selectOne(2);
//      System.out.println(dept.getDname());
      //2.插入操作
      Dept dept=new Dept();
      dept.setDname("张沅湲");
      dept.setLoc("郑州");
      mapper.insertDept(dept);
      session.commit();//实现增加 修改 删除
      //3.更新操作;
//      Dept dept=new Dept();
//      dept.setDeptno(3);
//      dept.setDname("张沅湲");
//      dept.setLoc("湖南");
//      mapper.updateDept(dept);
//      session.commit();
      //4.删除操作;
//      int i=mapper.deleteDept(3);
//      session.commit();
//      System.out.println(i);
    } catch (Exception e) {
      e.printStackTrace();
    }finally{
      session.close();
    }

  }
}

package org.mybatis.example.dao;

import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class SqlSessionFactoryUtil {
  private static SqlSessionFactory factory;
  public SqlSessionFactoryUtil() {}
  static{
    Reader reader=null;

    try {
      reader=Resources.getResourceAsReader("mybatisConfig.xml");
      factory=new SqlSessionFactoryBuilder().build(reader);
    } catch (Exception e) {
      e.printStackTrace();
    }finally{
      try {
        if(reader!=null)reader.close();
      } catch (Exception e2) {
        e2.printStackTrace();
      }
    }
  }

  public static SqlSession getSqlSession(){
    return factory.openSession();
  }
}

package org.mybatis.example.dao;

import java.util.List;

public interface DeptMapper {
  public Dept selectOne(int id);
  public int insertDept(Dept dept);
  public int updateDept(Dept dept);
  public int deleteDept(int id);
  public List<Dept>selectAllDepts();
  public List<Dept>selectByCriteria(String deptName);
}

<select id="selectAllDepts" resultType="org.mybatis.example.dao.Dept" >
    select deptno,dname,loc from dept
  </select>

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.mybatis.example.dao.Dept;
import org.mybatis.example.dao.DeptMapper;
import org.mybatis.example.dao.SqlSessionFactoryUtil;

public class Test3 {
  public static void main(String[] args) {
    SqlSession session=SqlSessionFactoryUtil.getSqlSession();
    try {
      DeptMapper mapper=session.getMapper(DeptMapper.class);
      List<Dept>depts=mapper.selectAllDepts();
      for(Dept dept:depts){
        System.out.println("部门名称:"+dept.getDname());
      }
    } catch (Exception e) {
      e.printStackTrace();
    }finally{
      session.close();
    }
  }
}

<!-- 按条件查询 -->
  <select id="selectByCriteria" parameterType="java.lang.String"
    resultType="org.mybatis.example.dao.Dept">
    select deptno,dname,loc from dept
    where dname like '%${_parameter}%'  
  </select>

import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.mybatis.example.dao.Dept;
import org.mybatis.example.dao.DeptMapper;
import org.mybatis.example.dao.SqlSessionFactoryUtil;

//按照条件进行查询;
public class Test4 {
  public static void main(String[] args) {
    SqlSession session=SqlSessionFactoryUtil.getSqlSession();
    try {
      DeptMapper mapper=session.getMapper(DeptMapper.class);
      List<Dept>depts=mapper.selectByCriteria("网络部");

      for(Dept dept:depts){
        System.out.println("部门名称:"+dept.getDname());
      }
    } catch (Exception e) {
      e.printStackTrace();
    }finally{
      session.close();
    }
  }
}