package com.sdzyg.dao;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class QueryLogin{
public Connection conn;
String table;
String username;
String password;
String url;
public QueryLogin(String table , String username , String password) throws SQLException, ClassNotFoundException
{
this.table = table;
this.username = username;
this.password = password;
}
public boolean query() throws SQLException, ClassNotFoundException
{
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/dms?user=root&password=1234"; //连接ODBC数据源
this.conn = DriverManager.getConnection(url); //连接url指定的数据库
Statement stmt = this.conn.createStatement(); //创建语句对象
ResultSet rset = stmt.executeQuery("SELECT * FROM " + table); //执行数据查询select语句，系统走到这步在不往下执行
for(int i = 0; rset.next(); i++) //从前向后访问获得每行数据
if(rset.getString(0).equals(username) &&rset.getString(2).equals(password)) //获得当前行指定列的值
return true;
else
return false;
rset.close();
stmt.close();
return false;
}
public void finalize() throws SQLException
{
this.conn.close();
}
}
------解决方案--------------------
表被锁了吧，或着数据量太大吧
------解决方案--------------------
- Java code
public boolean query() { ResultSet rset = null; Statement stmt = null; try { Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/dms?user=root&password=1234"; // 连接ODBC数据源 conn = DriverManager.getConnection(url); // 连接url指定的数据库 stmt = conn.createStatement();//创建语句对象 rset = stmt.executeQuery("SELECT * FROM " + table); // 执行数据查询select语句，系统走到这步在不往下执行 while (rset.next()) { // 从前向后访问获得每行数据 if (rset.getString(0).equals(username) && rset.getString(2).equals(password)){ // 获得当前行指定列的值 return true; } } return false; } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } finally { try { rset.close(); stmt.close(); } catch (SQLException e) { e.printStackTrace(); } } return false; }