mybatis中oracle實現分頁效果實例代碼

2019-11-26 12:30:07

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首先當我們需要通過xml格式處理sql語句時，經常會用到< ，<=，>，>=等符號，但是很容易引起xml格式的錯誤，這樣會導致后臺將xml字符串轉換為xml文檔時報錯，從而導致程序錯誤。

這樣的問題在iBatiS中或者自定義的xml處理sql的程序中經常需要我們來處理。其實很簡單，我們只需作如下替換即可避免上述的錯誤：

原符號	<	<=	>	>=	&	'	"
替換符號	<	<=	>	>=	&	'	"

數據庫的數據

一、邏輯分頁

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 {  /**   * 分頁查詢   */  public List<Student> selectall(RowBounds rb);//需要傳RowBounds 類型的參數}

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測試

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() {        //跳過幾行    int offset = 3;    //取幾行    int limit = 3;        RowBounds rb = new RowBounds(offset, limit);        List<Student> st=sm.selectall(rb);    for(Student tt:st){      System.out.println(tt);    }  }}

數據就取出來了

二、物理分頁。

用roacle是數據庫自己的分頁語句分頁

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 {    /**   * 分頁查詢   */  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測試

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() {    //當前第幾頁     Integer offset = 2;    //每頁行數    Integer limit = 3;        List<Student> st=sm.selectall(offset, limit);    for(Student tt:st){      System.out.println(tt);    }  }}

查詢結果