package?edu.ynu.dao;

import?java.sql.Connection;
import?java.sql.DriverManager;
import?java.sql.PreparedStatement;
import?java.sql.ResultSet;
import?java.sql.SQLException;
import?java.sql.Statement;

public?class?DB?{
	public?static?Connection?getConn（）?{
		Connection?conn?=?null;
		try?{
			Class.forName（“com.mysql.jdbc.Driver“）;

			conn?=?DriverManager
					.getConnection（“jdbc:mysql://localhost/bank?user=root&password=root“）;
		}?catch?（ClassNotFoundException?e）?{
			e.printStackTrace（）;
		}?catch?（SQLException?e）?{
			e.printStackTrace（）;
		}
		return?conn;
	}
	
	public?static?Statement?createStmt（Connection?conn）?{
		Statement?stmt?=?null;
		try?{
			stmt?=?conn.createStatement（）;
		}?catch?（SQLException?e）?{
			e.printStackTrace（）;
		}
		return?stmt;
	}
	
	public?static?ResultSet?executeQuery（Statement?stmt?String?sql）?{
		ResultSet?rs?=?null;
		try?{
			rs?=?stmt.executeQuery（sql）;
		}?catch?（SQLException?e）?{
			e.printStackTrace（）;
		}
		return?rs;
	}
	
	/*public?static?ResultSet?executeQuery（Connection?conn?String?sql）?{
		Statement?stmt?=?null;
		ResultSet?rs?=?null;
		try?{
			stmt?=?conn.createStatement（）;
			rs?=?stmt.executeQuery（sql）;
		}?catch?（SQLException?e）?{
			e.printStackTrace（）;
		}
		
//		finally?{
//			close（stmt）;
//		}
		
		
		return?rs;
	}*/
	
	public?static