readertype.java~2~

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 java.util.*;
import java.sql.*;
import com.actionForm.ReaderTypeForm;

public class ReaderType {
    private ConnDB conn=new ConnDB();
//查询数据
public Collection query(String strif){
    ReaderTypeForm readerTypeForm=null;
    Collection bookcaseColl=new ArrayList();
    String sql="";
    if(strif!="all" && strif!=null && strif!=""){
        sql="select * from tb_bookcase where "+strif+"";
    }else{
        sql="select * from tb_bookcase";
    }
    ResultSet rs=conn.executeQuery(sql);
    try {
        while (rs.next()) {
            readerTypeForm=new ReaderTypeForm();
            readerTypeForm.setID(Integer.valueOf(rs.getString(1)));
            readerTypeForm.setName(rs.getString(2));
            bookcaseColl.add(readerTypeForm);
        }
    } catch (SQLException ex) {
    }
    conn.close();
    return bookcaseColl;
}
//用于修改的查询
public ReaderTypeForm queryM(ReaderTypeForm bookCaseForm){
    ReaderTypeForm readerTypeForm=null;
    String sql="select * from tb_readerType where id="+readerTypeForm.getId()+"";
    System.out.println("修改时的SQL："+sql);
    ResultSet rs=conn.executeQuery(sql);
    try {
        while (rs.next()) {
            readerTypeForm=new ReaderTypeForm();
            readerTypeForm.setId(Integer.valueOf(rs.getString(1)));
            readerTypeForm.setName(rs.getString(2));
        }
    } catch (SQLException ex) {
    }
    conn.close();
    return readerTypeForm;
}
//添加数据
public int insert(ReaderTypeForm readerTypeForm){
String sql1="SELECT * FROM tb_readerType WHERE name='"+readerTypeForm.getName()+"'";
ResultSet rs = conn.executeQuery(sql1);
String sql = "";
int falg = 0;
try {
    if (rs.next()) {
        falg = 2;
    } else {
        sql ="Insert into tb_readerType (name) values('"+readerTypeForm.getName()+"')";
        falg = conn.executeUpdate(sql);
        System.out.println("添加书架信息的SQL：" + sql);
        conn.close();
    }
} catch (SQLException ex) {
    falg = 0;
}
System.out.println("falg:"+falg);
return falg;
}

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

}