PHP代码。怎么了？ [关闭]

问题描述：

I'm new to PHP and MySQL. I try to reach out MySQL table (3 column) and list rows. However following code does not show anything (blank page). Does any one has an idea?

<?php

$db = mysql_connect('localhost', 'root', 'root', 'database_name');

if(!$db){
die('Connect Error (' . mysqli_connect_errno() . ') '
        . mysqli_connect_error());
}

$result = "SELECT * FROM table_name";

$query = mysqli_query($result);

$row = mysqli_fetch_array($query, MYSQLI_NUM);

echo $row[0];

mysqli_free_result($result);

mysqli_close($db);

?>

我是PHP和MySQL的新手。我尝试伸出MySQL表（3列）并列出行。但是下面的代码没有显示任何内容（空白页）。有没有人有想法？ p>

 ＆lt;？php 
 
 $ db = mysql_connect（'localhost'，'root'，'root'，'database_name'）  ; 
 
if（！$ db）{
die（'Connect Error（'。mysqli_connect_errno（）。'）'
.mysqli_connect_error（））; 
} 
 
 $ result =“SELECT * FROM table_name  “; 
 
 $ query = mysqli_query（$ result）; 
 
 $ row = mysqli_fetch_array（$ query，MYSQLI_NUM）; 
 
echo $ row [0]; 
 
mysqli_free_result（$ result）; \  n 
mysqli_close（$ db）; 
 
？＆gt; 
  code>  pre> 
  div>

答

You're switching between mysql and mysqli.

You should be connecting to the database like this:

$db = new mysqli('host', 'username', 'password', 'database');

Run queries like:

$query = "SELECT * FROM my_table";
$result = $db->query($query);

Also, loop through the results like so:

while($row = mysqli_fetch_array($result)) {
     echo $row['column_name'];
}

There are more advanced concepts like prepared statements, but this should get you in the right direction.

答

I think firstly, check your data to make sure there is at least one row. If there is no row, echo $row[0] will result in error. But as you did not see anything on screen, better to check at php.ini for error_reporting settings. Change it to E_NOTICE and all errors/notice will be displayed to you.

答

You are mixing your database layer API.

MySQL_* and MySQLI_* Functions are different, contain different usages and such.

You should move away from MySQL_* Functions. Read the manual here:

http://www.php.net/manual/en/book.mysqli.php

You have the choice between object oriented or procedural style of MySQL.

Connect to the Database by reading about the __construct.

PHP代码。 怎么了？ [关闭]

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PHP代码。怎么了？ [关闭]