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
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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
}
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配置文件
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<?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>
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junit测试
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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);
}
}
}
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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
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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 );
}
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配置文件
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<?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>
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junit测试
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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);
}
}
}
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查询结果
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服务器之家。
原文链接：http://www.cnblogs.com/hq233/p/6753712.html?utm_source=tuicool&utm_medium=referral