mybatis中oracle实现分页效果实例代码

所属分类：软件编程 / java 阅读数： 25

收藏 0赞 0分享

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	<	<=	>	>=	&	'	"

数据库的数据

一、逻辑分页

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

二、物理分页。

用roacle是数据库自己的分页语句分页

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&lt;=#{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