readertypedao.java

这是一个功能比较齐全的图书管理系统

package com.dao;

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

import com.actionForm.ReaderTypeForm;

public class ReaderTypeDAO {
	private ConnDB conn = new ConnDB();

	// 查询数据
	public Collection query(String strif) {
		ReaderTypeForm readerTypeForm = null;
		Collection readerTypeColl = new ArrayList();
		String sql = "";
		if (strif != "all" && strif != null && strif != "") {
			sql = "select * from tb_readerType where " + strif + "";
		} else {
			sql = "select * from tb_readerType";
		}
		ResultSet rs = conn.executeQuery(sql);
		try {
			while (rs.next()) {
				readerTypeForm = new ReaderTypeForm();
				readerTypeForm.setId(Integer.valueOf(rs.getString(1)));
				readerTypeForm.setName(rs.getString(2));
				readerTypeForm.setNumber(rs.getInt(3));
				readerTypeColl.add(readerTypeForm);
			}
		} catch (SQLException ex) {
		}
		conn.close();
		return readerTypeColl;
	}

	// 用于修改的查询
	public ReaderTypeForm queryM(ReaderTypeForm readerTypeForm) {
		ReaderTypeForm readerTypeForm1 = 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()) {
				readerTypeForm1 = new ReaderTypeForm();
				readerTypeForm1.setId(Integer.valueOf(rs.getString(1)));
				readerTypeForm1.setName(rs.getString(2));
				readerTypeForm1.setNumber(rs.getInt(3));
				System.out.println(rs.getInt(3));
			}
		} catch (SQLException ex) {
		}
		conn.close();
		return readerTypeForm1;
	}

	/* 添加读者类别信息 */
	public int insert(ReaderTypeForm readerTypeForm) {
		/*首先查询读者类别名称是否已经存在*/
		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,number) values('"
						+ readerTypeForm.getName() + "',"
						+ readerTypeForm.getNumber() + ")";
				falg = conn.executeUpdate(sql);
				System.out.println("添加读者类型的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() + "',number="
				+ readerTypeForm.getNumber() + " 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_1 = "SELECT * FROM tb_reader WHERE typeid="
				+ readerTypeForm.getId() + "";
		ResultSet rs = conn.executeQuery(sql_1);
		int flag = 0;
		try {
			if (!rs.next()) {
				String sql = "Delete from tb_readerType where id="
						+ readerTypeForm.getId() + "";
				flag = conn.executeUpdate(sql);
				System.out.println("删除时的SQL：" + sql);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return flag;
	}

}