promotionmanager.java

一个简单的网上订书系统 java的课程设计

package proxy;

import java.sql.*;

import connector.Executor;
import connector.Searcher;

public class PromotionManager {
	private static Searcher s = new Searcher();
	private static ExecutorProxy e = new ExecutorProxy();

	public static int[] insertPromotions(Statement stmt) throws SQLException,
			BatchUpdateException {

/*		String insert = "";
		for (int i = 0; i < 5; i++, insert = "") {
			insert += "insert into Promotion values ('Pn" + i + "'," + i
					+ ",'2007-5-0" + i + "'); ";
			stmt.addBatch(insert);
		}
		return stmt.executeBatch();*/
		insert("Pno001",0.90,"2006-12-09");
		insert("Pno002",0.75,"2007-02-04");
		insert("Pno003",0.80,"2006-02-23");
		insert("Pno004",0.60,"2007-04-21");
		insert("Pno005",0.95,"2006-07-03");
		insert("Pno006",0.65,"2006-07-23");
		insert("Pno007",0.85,"2007-05-20");
		insert("Pno008",0.80,"2006-12-27");
		insert("Pno009",0.50,"2007-01-01");
		insert("Pno010",0.85,"2006-04-03");

		return null;
	}

	public static int insert(String Pno, double discount, String duration)
			throws SQLException {
		String query = "insert into Promotion values(" + Checker.checkNull(Pno)
				+ "," + discount + "," + Checker.checkNull(duration) + ");";
		return e.execute(query);
	}

	public static int insert(String[] args) {
		if (args.length != 3) {
			System.err.print("PromotionManeger arguments input error.");
			return -1;
		}
		String query = "insert into Promotion values(";
		return e.execute(Checker.argsInsert(query, args));
	}

	public static int deleteByPno(String Pno) {
		String query = "delete from Promotion where Pno ="
				+ Checker.checkNull(Pno) + ";";
		return e.execute(query);
	}

	public static int update(String Pno, double discount, String duration) {
		
		String s1= Checker.checkNull(Pno);

		if (s1 == Checker.nullStr) {
			System.err
					.println("PromotionManager update error: Promotion ID is null");
			return -1;
		}

		String s2= Checker.checkNull(duration);
		
		if (discount == 0.0 && s2 == Checker.nullStr) {
			System.err
					.println("PromotionManager update error: Don't update any date.");
			return -1;
		}
		
		String tmp1 = "", tmp2 = "";

		if (discount != 0.0)
				tmp1 = " discount = " + discount;

		if (s2 != Checker.nullStr) 
			tmp2 = " duration = " + Checker.updateOnNull(duration);

		String query = "update Promotion set" + tmp1
				+ Checker.addComma(String.valueOf(discount), duration) + tmp2 + " where Pno = "
				+ s1 + ";";
		System.out.println(query);
		return e.execute(query);

	}
	
	public static String getNewPromotionID(){
		String ID = pre;
		String last = s.getLastID(TablesManager.promotion);
		if(last == null) return "Pno000";
 		int num = Integer.parseInt(last.substring(3));
		num++;
		last = String.valueOf(num);
		for(int i = last.length() ;i< 3;i++)
			ID = ID.concat("0");
		ID = ID.concat(last);
		return ID;
	}

	private static final String pre = "Pno";
}