operate.java

网上考试系统文件版

/*
 * Created on 2006-4-6
 *
 * To change the template for this generated file go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
package todb;
import java.sql.*;

/**
 * @author admin
 *
 * To change the template for this generated type comment go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
public class Operate {
	Connection conn = null;
	ResultSet rs = null;

	public Operate() {
	}

	public ResultSet executeQuery(String sql) throws Exception {
		rs = null;
		try {
			if (conn != null)
				conn.close();
			conn = DbUtil.connectToDb();
			Statement stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
		} catch (SQLException ex) {
			System.err.println("bbsdb.executeQuery:" + ex.getMessage());
		}

		return rs;
	}


	public void executeUpdate(String sql) throws Exception
		{
			try
			{
				if (conn != null)
				{
					conn.close();
				}
				conn = DbUtil.connectToDb();
				Statement stmt = conn.createStatement();
				stmt.executeUpdate(sql);
				conn.commit();
			}
			catch(SQLException ex)
			{
				System.err.println("bbsdb.executeUpdate: " + ex.getMessage());
			}
		}
		

	public int getRowNum(String table) throws Exception {
		int rsnum = 0;
		rs = null;
		try {
			String sql = "SELECT COUNT(*) FROM " + table + " ";
			if (conn != null) {
				conn.close();
			}
			conn = DbUtil.connectToDb();
			Statement stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
			while (rs.next()) {
				rsnum = rs.getInt(1);
			}
		} catch (SQLException ex) {
			System.err.println("bbsdb.getResultNum:" + ex.getMessage());
		}
		return rsnum;
	}

	public void finalize()
	{
		try
		{
			if (conn != null)
				conn.close();
		}catch (SQLException ex){
				System.err.println("bbsdb.executeUpdate: " + ex.getMessage());
			}
	}


}