bookcasedao.java~43~

图书馆管理系统 第1章 系统简介 图书馆是各大高等院校的重要组成部门

package com.dao;

import com.core.ConnDB;
import com.actionForm.BookCaseForm;
import java.util.*;
import java.sql.*;

public class BookCaseDAO {
    private ConnDB conn=new ConnDB();
    //查询全部数据
    public Collection query(String strif){
        BookCaseForm bookCaseForm1=null;
        Collection bookcaseColl=new ArrayList();
        String sql="";
        if(strif=="all" || strif==null || strif==""){
            sql="select * from tb_bookcase";
        }else{
            sql="select * from tb_bookcase where "+strif+"";
        }
        ResultSet rs=conn.executeQuery(sql);
        try {
            while (rs.next()) {
                bookCaseForm1=new BookCaseForm();
                bookCaseForm1.setId(Integer.valueOf(rs.getString(1)));
                bookCaseForm1.setName(rs.getString(2));
                bookcaseColl.add(bookCaseForm1);
            }
        } catch (SQLException ex) {
        }
        conn.close();
        return bookcaseColl;
    }
    //带条件的查询
    public Collection queryif(BookCaseForm bookCaseForm){
        BookCaseForm bookCaseForm1=null;
        Collection bookcaseColl=new ArrayList();
        String sql="select * from tb_bookcase where id="+bookCaseForm.getId()+"";
        ResultSet rs=conn.executeQuery(sql);
        try {
            while (rs.next()) {
                bookCaseForm1=new BookCaseForm();
                bookCaseForm1.setId(Integer.valueOf(rs.getString(1)));
                bookCaseForm1.setName(rs.getString(2));
                bookcaseColl.add(bookCaseForm1);
            }
        } catch (SQLException ex) {
        }
        conn.close();
        return bookcaseColl;
    }
    //用于修改的查询
    public BookCaseForm queryM(BookCaseForm bookCaseForm){
        BookCaseForm bookCaseForm1=null;
        String sql="select * from tb_bookcase where id="+bookCaseForm.getId()+"";
        System.out.println("修改时的SQL："+sql);
        ResultSet rs=conn.executeQuery(sql);
        try {
            while (rs.next()) {
                bookCaseForm1=new BookCaseForm();
                bookCaseForm1.setId(Integer.valueOf(rs.getString(1)));
                bookCaseForm1.setName(rs.getString(2));
            }
        } catch (SQLException ex) {
        }
        conn.close();
        return bookCaseForm1;
    }
   //添加数据
    public int insert(BookCaseForm bookCaseForm){
    String sql="Insert into tb_bookcase (name) values('"+bookCaseForm.getName()+"')";
    int flag=conn.executeUpdate(sql);
    conn.close();
    return flag;
}

    //修改数据
    public int update(BookCaseForm bookCaseForm){
    String sql="Update tb_bookcase set name='"+bookCaseForm.getName()+"' where id="+bookCaseForm.getId()+"";
    int falg=conn.executeUpdate(sql);
    System.out.println("修改数据时的SQL："+sql);
    conn.close();
    return falg;
}
    //删除数据
    public int delete(BookCaseForm bookCaseForm){
    String sql="Delete from tb_bookcase where id="+bookCaseForm.getId()+"";
    int falg=conn.executeUpdate(sql);
    System.out.println("删除时的SQL："+sql);
    return falg;
}

}