使用php从数据库获取数据

Question

我想从数据库中获取数据。 当我上传文件时，页面没有改变。 我哪里错了？

verifycheck.php

<?php
$con=mysql_connect ("###", "###", "###");
mysql_select_db ("db_name", $con);


$result = mysql_query($con,"SELECT * FROM db_tablename");


echo "<table border='1'>
<tr>
<th>username</th>
<th>email</th>
<th>password</th>
<th>confirm_password</th>
</tr>";

while($row = mysql_fetch_assoc($result)) {
  echo "<tr>";
  echo "<td>" . $row['username'] . "</td>";
  echo "<td>" . $row['email'] . "</td>";
  echo "<td>" . $row['password'] . "</td>";
  echo "<td>" . $row['confirm_password'] . "</td>";
  echo "</tr>";
}

echo "</table>";

mysql_close($con);
?>

Answer 1

连接对象应该是第二个参数，查询字符串应该是第一个参数。

尝试这个

$result = mysql_query("SELECT * FROM db_tablename",$con);

代替

$result = mysql_query($con,"SELECT * FROM db_tablename");

不建议使用Mysql函数，将来会删除Mysqli或PDO来防止sql注入

Answer 2

从mysql_query删除$con,

由于mysql_query()期望第一个参数是SQL查询，而不是SQL连接。

$result = mysql_query("SELECT * FROM db_tablename");

Answer 3

请检查您的连接参数为localhost，用户名密码，数据库，并更改

  $result = mysql_query($con,"SELECT * FROM db_tablename"); 
   as 
   $result = mysql_query("SELECT * FROM db_tablename",$con);