How to solve the problem in php if there is no database in the array

php Solution if there is no database in the array: 1. Create a PHP sample file; 2. Create a MySQL database and a link to the database, complete through the "mysql_connect()" function, the syntax is "mysql_connect( servername,username,password);"; 3. Import the PHP file into the database and run the relevant code.

Operating system for this tutorial: Windows 10 system, PHP version 8.1.3, Dell G3 computer

PHP is "Hypertext Preprocessor", It is a general-purpose open source scripting language. PHP is a scripting language executed on the server side. It is similar to C language and is a commonly used website programming language. PHP's unique syntax mixes C, Java, Perl, and PHP's own syntax. What should I do if php cannot find the database?

php Solution if there is no database in the array

The free MySQL database is usually used through PHP.

Connecting to a MySQL database

Before you can access and process data in the database, you must create a connection to the database.

In PHP, this task is completed through the mysql_connect() function.

Syntax

mysql_connect(servername,username,password);

Parameters	Description
servername	Optional. Specifies the server to connect to. The default is "localhost:3306".
username	Optional. Specifies the username to log in with. The default value is the name of the user who owns the server process.
password	Optional. Specifies the password to use for login. The default is "".

Note: Although there are other parameters, the most important parameters are listed above. Please visit the PHP MySQL Reference Manual provided by W3School for more details.

Example

In the following example, we store the connection in a variable ($con) for later use in the script. If the connection fails, the "die" part will be executed:

<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die(&#39;Could not connect: &#39; . mysql_error());
  }
// some code
?>

Close the connection

As soon as the script ends, the connection will be closed. If you need to close the connection early, please use the mysql_close() function.

<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die(&#39;Could not connect: &#39; . mysql_error());
  }
// some code
mysql_close($con);
?>

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