mydb.java

这是一个用java语言开发的运动员成绩统计系统

package com.DBManager;

import java.awt.Frame;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;



public class MyDB {
    private String driver="org.gjt.mm.mysql.Driver"; //Driver
	private String user="root";// database username
	private String password="111111";//database password
	private String url="jdbc:mysql://localhost:3306/athlete";//connction url
	
	Connection con;
	Statement stmt;
	
	public MyDB(){
		 
	}
	public boolean connectDB(){
		try {
			Class.forName(driver);
			con=DriverManager.getConnection(url,user,password);
			stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
		} catch (Exception e) {
			System.out.println("连接失败");
		   
		    return false;
		}
		return true;
	}
	
	public ResultSet executeQuery(String sql){
		ResultSet rs=null;
		 try {
			rs=stmt.executeQuery(sql);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return rs;
	}
	public boolean executeUpdate(String sql){
		try {
			stmt.executeUpdate(sql);
		} catch (SQLException e) {
			
			e.printStackTrace();
			return false;
		}
		return true;
	}
	public boolean close(){
		try {
			con.close();
		} catch (SQLException e) {
			e.printStackTrace();
			return false;
			
		}
		return true;
	}
	
	public int rowCount(String sql)
	{
		ResultSet rs=executeQuery(sql);
		int count=0;
		try {
			rs.last();
			count=rs.getRow();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return count;
	}
	public String getString(String sql,String col){
		ResultSet rs=this.executeQuery(sql);
		try {
			if(rs.next())
				return rs.getString(col);
		} catch (SQLException e) {
			
			e.printStackTrace();
		}
		return "";
	}
	public int getInt(String sql,String col){
		ResultSet rs=this.executeQuery(sql);
		try {
			if(rs.next())
				return rs.getInt(col);
		} catch (SQLException e) {
			
			e.printStackTrace();
		}
		return -1;
	}
	public static void main(String args[]){
		MyDB db=new MyDB();
		db.connectDB();
		ResultSet r=db.executeQuery("select * from user");
		
		try {
			while(r.next()){
				try {
					System.out.println(r.getString("name"));
				
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
   db.close();
	}
	
}