mybatis中oracle实现分页效果实例代码

2019-11-26 12:30:07

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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<=#{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