Question

用jsp怎样连接mysql数据库？

<%@ page contentType="text/html; charset=gb2312" %>

<%@ page language="java" %>

<%@ page import="com.mysql.jdbc.Driver" %>

<%@ page import="java.sql.*" %>

<%

//驱动程序名

String driverName="com.mysql.jdbc.Driver";

//数据库用户名

String userName="root";

//密码

String userPasswd="123";

//数据库名

String dbName="mysql";

//表名

String tableName="mysql";

//联结字符串

String url="jdbc:mysql://localhost/"+mysql+"?user="+root+"&password="+123;

Class.forName("com.mysql.jdbc.Driver").newInstance();

Connection connection=DriverManager.getConnection(url);

Statement statement = connection.createStatement();

String sql="SELECT * FROM "+mysql;

ResultSet rs = statement.executeQuery(sql);

//获得数据结果集合

ResultSetMetaData rmeta = rs.getMetaData();

//确定数据集的列数，亦字段数

int numColumns=rmeta.getColumnCount();

// 输出每一个数据值

out.print("id");

out.print("|");

out.print("num");

out.print("<br>");

while(rs.next()) {

out.print(rs.getString(1)+" ");

out.print("|");

out.print(rs.getString(2));

out.print("<br>");

}

out.print("<br>");

out.print("数据库操作成功，恭喜你");

rs.close();

statement.close();

connection.close();

%>

请问一下怎样解决？先谢了啊！
我按照下面3位的见解改后还是出现了这样的报错：
An error occurred at line: 34 in the jsp file: /1.jsp
mysql cannot be resolved
32: //联结字符串
33:
34: String url="jdbc:mysql://localhost:3306/"+mysql+"?user="+root+"&password="+123;
35:
36: Class.forName("com.mysql.jdbc.Driver").newInstance();
请问一下错在哪？

Answer 1

String sql="SELECT * FROM "+mysql;

你没有定义过mysql 变量吧！
应该是：String sql="SELECT * FROM "+tableName吧;

Answer 2

String url="jdbc:mysql://localhost/"+mysql+"?user="+root+"&password="+123;

mysql端口默认是3306 应该是

String url="jdbc:mysql://localhost:3306/"+mysql+"?user="+root+"&password="+123;

Answer 3

http://adgege.qupan.com/166544.html
该电子书里有一章很详细地讲了你的问题。！！

Answer 4

爱莫能助