sqlselect.java

java 查询数据库 mysql使用案例

package com.test;

import java.sql.*;

public class sqlselect {

	  public Connection getCon() {
		  
		  
		  Connection con=null;
		  
		  String url = "jdbc:mysql://www.busycode.com:3306/bigpapa";
	    try {

	      Class.forName("org.gjt.mm.mysql.Driver").newInstance();
	      
	      con = DriverManager.getConnection(url,"root","root");
	      
	    }catch (ClassNotFoundException e) {
	    	System.err.println("class not found:" + e.getMessage());}
	    catch (SQLException a) {
		      System.err.println("sql exception:" + a.getMessage());
		    }
	    catch (Exception d) {
		      System.err.println("sql exception:" + d.getMessage());
		    }

	    return con;
	  }
	  
	  
	/**

	* 执行一条简单的查询语句

	* 返回取得的结果集

	*/

	  public ResultSet executeQuery(String sql) {
		
		 Statement stmt=null;
	    ResultSet rs = null;
	    Connection con= this.getCon();
		try {
			stmt = con.createStatement();

	      rs = stmt.executeQuery(sql);
	      
	    }

	    catch (SQLException e) {

	      e.printStackTrace();

	    }
	    return rs;
	  }
	  

	  public boolean executeUpdate(String sql) {
		  Connection con=this.getCon();
		  Statement stmt=null;
		  boolean v = false;
		try {
			stmt = con.createStatement();
		
	      v = stmt.executeUpdate(sql) > 0 ? true : false;
	    }

	    catch (SQLException e) {

	      e.printStackTrace();

	    }

	    finally {

	      return v;

	    }

	  }

}