java实现mysql数据库增删改查

1.连接数据库:

import java.sql.Connection;
import java.sql.DriverManager;

public class DBConnection {
	static String driver = "com.mysql.jdbc.Driver";
	static String url= "jdbc:mysql://localhost:3306/mydatabase01?useUnicode=true&characterEncoding=utf-8";
	static  String user = "root";
	static  String password = "123456";
	    
	    public Connection conn;
	    
	    static {
	    	
	    	try {
	    		System.out.println("驱动加载开始=====================");
				Class.forName(driver);
				System.out.println("驱动加载完毕==================");
				
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}// 加载驱动程序
	    }

	    public DBConnection() {

	        try {
	            
	            conn = (Connection) DriverManager.getConnection(url, user, password);// 连接数据库
	            
	            if(!conn.isClosed())
	                System.out.println("Succeeded connecting to the Database!"); 
	        } catch (Exception e) {
	            e.printStackTrace();
	        }
	    }
	    
	    public void close() {
	        try {
	            this.conn.close();
	        } catch (Exception e) {
	            e.printStackTrace();
	        }
	    }

}

2.数据库操作

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;



public class MysqlUtil {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String sqlstr = "INSERT  INTO student  (stuname,class,sex,major,mathstore,engstore,yuwenstore) VALUES('";
		
		sqlstr += "赵大众','大四1班','2','计算机专业','50','80','100')";
	
		String delstr = " insert into student (stuname,class,sex,major,mathstore) values ('彭小杰','初三','1','全专业',90) ";
		
	
		System.out.println(add(delstr));
	}
	
	
    
    //插入操作
    public static int add(String sql) {
        int i=0;
     
        DBConnection db = new DBConnection();
        try {        
            PreparedStatement preStmt = (PreparedStatement) db.conn.prepareStatement(sql);
            preStmt.executeUpdate();
            //Statement statement = (Statement) db.conn.createStatement();
            //statement.executeUpdate(sql);
            
            preStmt.close();
            db.close();//关闭连接 
            i = 1;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return i;//返回影响的行数，1为执行成功
    }
    
    //查找操作
    public static List< Map > show(String sql, String[] params){
        // String sql ="select * from employee";
    	
    	
    	List< Map > listmap = new ArrayList<>();
    	
         DBConnection db = new DBConnection();
         ResultSet rs = null;
         System.out.println("-----------------");
         System.out.println("姓名" +"\t"+ "邮箱" +"\t"+ "日期");
         System.out.println("-----------------");
         
         try {
            Statement stmt = (Statement) db.conn.createStatement();
            rs = (ResultSet) stmt.executeQuery(sql);//返回链表
            while(rs.next()){
            	
            	Map map = new HashMap();
            	for(int i = 0; i < params.length; i++) {
            		
            		map.put(params[i], rs.getString(params[i]));
            	}
            	listmap.add(map);
            }
            rs.close();
            db.close();//关闭连接 
        } catch (SQLException e) {
            e.printStackTrace();
        }
		return listmap; 
         
     
    }
    //更新操作
    public static int update( String sql ) {
        int i =0;
       // String sql="update employee set email=?,pwd=? where name=?";
        DBConnection db = new DBConnection();
        
        try {
            PreparedStatement preStmt = (PreparedStatement) db.conn.prepareStatement(sql);
//            preStmt.setString(1, uemail);
//            preStmt.setString(2, upwd);
//            preStmt.setString(3, uname);
            preStmt.executeUpdate();
            
            preStmt.close();
            db.close();//关闭连接 
            i = 1;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return i;//返回影响的行数，1为执行成功
    }
    //删除操作
    public static int del(String sql) {
        int i=0;
      //  String sql="delete from employee where name=?";
        DBConnection db = new DBConnection();
        try {    
            PreparedStatement preStmt = (PreparedStatement) db.conn.prepareStatement(sql);
         
            preStmt.executeUpdate();
            
            preStmt.close();
            db.close();//关闭连接 
            
            i = 1;
        } catch (SQLException e){
            e.printStackTrace();
        }
        return i;//返回影响的行数，1为执行成功
    }
    
    
    public static List