sqlhelper.java

桌面销售管理系统 JDBC的基本应用

package dal;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.lang.ClassNotFoundException;
public class SQLHelper
{
	private static final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";
	private static final String URL="jdbc:sqlserver://localhost:1433;DatabaseName=Shop";
	private static final String USER_NAME="likun";
	private static final String USER_PWD="111111";
	private static Connection conn=null;
	
	//此方法用来获取一个连接对象
	public static Connection getConn()
	{
		try
		{
			Class.forName(DRIVER);
			conn=DriverManager.getConnection(URL,USER_NAME,USER_PWD);
		}
		catch(ClassNotFoundException e)
		{
		
			System.out.println (e);
		}
		catch(SQLException e)
		{
			System.out.println (e);
		}
		finally
		{
			return conn;
		}
	}
	
	//用于执行一条SQL语句
	//参数：一个命令对象
	//返回值：执行成功，返回true，否则返回false
	public static boolean executeUpdate(PreparedStatement ps)
	{
		boolean result=true;
		try
		{
			int i=ps.executeUpdate();
			if(i>0)
			{
				result=true;
			}
			else
			{
				result=false;
			}
		}
		catch(SQLException e)
		{
			System.out.println (e);
		}
		finally
		{
			coloseConn();
		}
		return result;
	}
	
	//用于查询一条记录
	//参数：一个命令对象
	//返回值:记录集对象
	public static ResultSet executeQuery(PreparedStatement ps)
	{
		ResultSet rs=null;
		try
		{
			rs=ps.executeQuery();
		}
		catch(SQLException e)
		{
			System.out.println (e);
		}
		return rs;
	}
	
	//此方法用来关闭连接
	public static void coloseConn()
	{
		try
		{
			if(conn!=null)
			{
				conn.close();
			}
		}
		catch(SQLException e)
		{
			System.out.println (e);
		}
	}
	
}