Azure PHP MySQL In-App - can't connect to MySQL from PHP

Question

I'm using Azure for a PHP web-app that is coupled to a MySQL database. We'd like to try to use the MySQL in-app option to store our data. However, I'm having difficulties connecting to the DB from PHP code. The blog post by Microsoft for connecting to the MySQL database doesn't seem to work for me.

The blog has a piece of code written that defines some global constants by parsing an environment variable. This environment variable, however, seems to have just an empty value instead of the full string of parameters to connect, i.e. "Database=localdb;Data Source=127.0.0.1:49782;User Id=azure;Password=password". I can fill in this info manually into my code to try to connect, but this isn't robust since the port of the source can change.

So my real issue lies in that the "MYSQLCONNSTR_localdb" environment variable doesn't have the right value, even after following all of the steps in the blog post. What am I missing here?

Thank you in advance!

The code I use for testing:

<?php

// From the blog-post
$connectstr_dbhost = '';
$connectstr_dbname = '';
$connectstr_dbusername = '';
$connectstr_dbpassword = '';

foreach ($_SERVER as $key => $value)
{
    if (strpos($key, "MYSQLCONNSTR_") !== 0)
    {
        continue;
    }

    $connectstr_dbhost = preg_replace("/^.*Data Source=(.+?);.*$/", "\\1", $value);
    $connectstr_dbname = preg_replace("/^.*Database=(.+?);.*$/", "\\1", $value);
    $connectstr_dbusername = preg_replace("/^.*User Id=(.+?);.*$/", "\\1", $value);
    $connectstr_dbpassword = preg_replace("/^.*Password=(.+?)$/", "\\1", $value);

    echo $value;
}

define('DB_NAME', $connectstr_dbname);
define('DB_USER', $connectstr_dbusername);
define('DB_PASSWORD', $connectstr_dbpassword);
define('DB_HOST', $connectstr_dbhost);

// Custom testing
echo $connectstr_dbname."\n";
echo $connectstr_dbusername."\n";
echo $connectstr_dbpassword."\n";
echo $connectstr_dbhost."\n";

$dbConnection = $dbLink = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);

if ($dbConnection)
{
    echo "Successfully connected to the database.\n";
}
else
{
    echo "Failed to connect to the database.\n";
}
?>

EDIT: updated the code and removed part of the problem that was caused by a malformed if-statement thanks to @ Aaron Chen - MSFT

Aaron Chen · Accepted Answer · 2017-04-14 10:00:11Z

2

You have made a mistake in the if statement.

if (!$dbConnection)
{
    echo "Successfully connected to the database.\n";
}
else
{
    echo "Failed to connect to the database.\n";
}

In this code, if a proper connection to MySQL was made, it will go to echo "Failed to connect to the database.\n".

Please use the following instead:

if (!$dbConnection)
{
    echo "Failed to connect to the database.\n";
}
else
{
    echo "Successfully connected to the database.\n";
}

When I replaced \n with <br>, I got the following:

Here's return of phpinfo().

edited Apr 14, 2017 at 10:00

answered Apr 12, 2017 at 2:57

Aaron Chen

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5 Comments

Jan Discart Over a year ago

I can't believe I made that mistake. Although it helped getting more correct feedback, it didn't solve the issue of the MySQL connection string not being available.

Aaron Chen Over a year ago

What exactly are you expecting to happen? What do you mean by the MySQL connection string not being available?

Jan Discart Over a year ago

Well, according to the blog-post I linked in my problem, when enabling the MySQL In-app feature, the 'MYSQLCONNSTR_localdb' server variable would be set with a string that contains the connection information to the db. The first part of the code is directly copied from the post to retrieve that info. The second part, which contains some echo statements to display that info all return empty values. Directly printing out the unparsed string also yields an empty string.

Aaron Chen Over a year ago

Trying to use <br> Instead of \n.

Jan Discart Over a year ago

I found the solution to my problem. Thanks for the offered help and effort you put into your answer.

Jan Discart · Accepted Answer · 2017-04-14 10:07:21Z

0

Apparently, testing local PHP scripts from the web-console does not make Azure set the necessary values in the $_SERVER array.

Before testing a web-service based script, I made local scripts that ran on the server, but only in a local PHP environment, and not the PHP environment invoked when a request comes in for a web page.

answered Apr 14, 2017 at 10:07

Jan Discart

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