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mybatis中oracle实现分页效果实例代码

  • 时间:2020-05-14 23:15 编辑: 来源: 阅读:
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摘要:mybatis中oracle实现分页效果实例代码
首先当我们需要通过xml格式处理sql语句时,经常会用到< ,<=,>,>=等符号,但是很容易引起xml格式的错误,这样会导致后台将xml字符串转换为xml文档时报错,从而导致程序错误。 这样的问题在iBatiS中或者自定义的xml处理sql的程序中经常需要我们来处理。其实很简单,我们只需作如下替换即可避免上述的错误:
原符号  <  <=   > >=   &   '   "
替换符号 < <= > >= & ' "
[b]数据库的数据[/b] [img]http://img.1sucai.cn/uploads/article/2018010710/20180107100156_0_97155.png[/img] [b]一、逻辑分页[/b] 接口
package com.dao;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.RowBounds;

import com.model.Student;

public interface StudentMapper {
  /**
   * 分页查询
   */
  public List<Student> selectall(RowBounds rb);//需要传RowBounds 类型的参数

}

配置文件
<?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.StudentMapper">
 
  <select id="selectall" resultType="student" >
    select * from student
  </select>
  
 </mapper>
JUnit测试
package com.util;

import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.dao.StudentMapper;
import com.model.Student;

public class Jtest {
  private SqlSession ss;
  private StudentMapper sm;
  @Before
  public void setUp() throws Exception {
    ss=SqlSessionUtil.getSqlSession();
    sm=ss.getMapper(StudentMapper.class);
    
  }

  @After
  public void tearDown() throws Exception {
    ss.commit();
    ss.close();
  }

  @Test
  public void selectall() {
    
    //跳过几行
    int offset = 3;
    //取几行
    int limit = 3;
    
    RowBounds rb = new RowBounds(offset, limit);    
    List<Student> st=sm.selectall(rb);
    for(Student tt:st){
      System.out.println(tt);
    }
  }

}

数据就取出来了 [img]http://img.1sucai.cn/uploads/article/2018010710/20180107100156_1_2573.png[/img] [b]二、物理分页。[/b] 用roacle是数据库自己的分页语句分页 [img]http://img.1sucai.cn/uploads/article/2018010710/20180107100156_2_5440.png[/img]   接口
package com.dao;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.RowBounds;

import com.model.Student;

public interface StudentMapper {
  
  /**
   * 分页查询
   */
  public List<Student> selectall(Integer offset, Integer limit );
  
}

配置文件
<?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.StudentMapper">
  
  <select id="selectall" resultType="student">
    select * from (select t.*,rownum rownu from STUDENT t 
    where rownum<=#{param1}*#{param2})tt
    where tt.rownu>(#{param1}-1)*#{param2}
  </select>

 </mapper>
JUnit测试
package com.util;

import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.dao.StudentMapper;
import com.model.Student;

public class Jtest {
  private SqlSession ss;
  private StudentMapper sm;
  @Before
  public void setUp() throws Exception {
    ss=SqlSessionUtil.getSqlSession();
    sm=ss.getMapper(StudentMapper.class);
    
  }

  @After
  public void tearDown() throws Exception {
    ss.commit();
    ss.close();
  }
  
  @Test
  public void selectall() {
    //当前第几页 
    Integer offset = 2;
    //每页行数
    Integer limit = 3;    
    List<Student> st=sm.selectall(offset, limit);
    for(Student tt:st){
      System.out.println(tt);
    }
  }

}

查询结果 [img]http://img.1sucai.cn/uploads/article/2018010710/20180107100157_3_36496.png[/img] 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持编程素材网。
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