zoukankan      html  css  js  c++  java
  • MySql中查询语句实现分页功能

    import java.util.*;
    import java.sql.*;

    public class FruitDao {
        private Connection conn;
        private PreparedStatement pre;
        private ResultSet rs;
        public FruitDao() throws Exception {
            conn = DBConnection.aa();
        }
        //返回总页数
        public int yeshu(int meiyegeshu) throws SQLException{
            //求有多少行
            int yeshu = 0;
            String sql = "select count(*)from fruit";
            pre = conn.prepareStatement(sql);
            rs = pre.executeQuery();
            rs.next();
            int hangshu = rs.getInt(1);
            //求有多少页
            yeshu = (int)Math.ceil(1.0*hangshu/meiyegeshu);//取上限值
            conn.close();
            return yeshu;    
        }
        
        
        //返回指定页的数据
        public ArrayList<Fruit> selest(int yaozhaoyeshu,int meiyegeshu) throws Exception{
            ArrayList<Fruit> list = new ArrayList<Fruit>();
            String sql = "select * from fruit limit ?,?";
            pre = conn.prepareStatement(sql);
            pre.setInt(1, meiyegeshu*(yaozhaoyeshu-1));//要找第几页,从多少行开始
            pre.setInt(2, meiyegeshu);//找的页有多少行
            rs = pre.executeQuery();
            while (rs.next()){
                Fruit data = new Fruit();
                data.setIds(rs.getString(1));
                data.setName(rs.getString(2));
                data.setPrice(rs.getDouble(3));
                data.setSource(rs.getString(4));
                data.setNumbers(rs.getInt(5));
                data.setImage(rs.getString(6));
                list.add(data);
            }
            conn.close();    
            return list;
        }
        

    }

  • 相关阅读:
    [vue Debugger] sourcemap
    [vuex]持久化存储
    [vuex]字典值封装到vuex缓存
    [vue]常用指令集合
    VSCode插件集合
    [element-ui] 表格点击出现编辑效果实现
    [pdf] 插件实现pdf上传预览、打印
    [html] 特殊字符
    [element-ui] 穿梭框对象重复不添加方案
    Redis持久化
  • 原文地址:https://www.cnblogs.com/stsinghua/p/6265045.html
Copyright © 2011-2022 走看看