mybatis中oracle实现分页效果

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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<<=>>=&'"

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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

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