There be a situation when there are different databases present and you have to select one of them to work on. So after MySql connection you can do the following things:
Selecting MySQL Database from Command Prompt:
This is very simple to select a particular database from mysql> prompt. You can use SQL command use to select a particular database.
[bha size='468x60' variation='01' align='none']Example:
Here is an example to select database called “DATABASE TUTORIALS”:
[root@host]# mysql -u root -p
Enter password:******
mysql> use DATABASE TUTORIALS;
Database changed
mysql>
As you select “DATABASE TUTORIALS” database and all the subsequent operations will be performed on DATABASE TUTORIALS.
PHP Script:
PHP provides function mysql_select_db to select a database. It returns TRUE on success or FALSE on failure.
Syntax:
bool mysql_select_db( db_name, connection );
| Command | Detail |
| db_name | MySQL Database name is to be selected by the user |
| connection | Optional – then last opened connection by mysql_connect will be used. |
Example:
How to select a database.
[php]
<!--?php
$dbhost = 'localhost';
$dbusername = 'guest';
$dbpassword = 'guest123';
$con = mysql_connect($dbhost, $dbusername, $dbpassword);
if(! $con )
{
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_select_db( ' DATABASE TUTORIALS' );
mysql_close($con);
?-->
[/php]Frequently Asked Questions
How does this PHP project work?
Built with vanilla PHP (no framework) and MySQL backend. Standard structure: form HTML, PHP script handlers, MySQL via PDO or mysqli, sessions for auth, Bootstrap for responsive layout. Ready to extend for BSIT capstone scope.
What PHP and MySQL versions does this project require?
Most projects in this batch run on PHP 7.4 to PHP 8.2 with MySQL 5.7+ or MariaDB 10+. A few older projects need PHP 5.6 (deprecated, use XAMPP 7.x). To run: install XAMPP / WAMP / Laragon, extract project to htdocs, import the included .sql file via phpMyAdmin, edit the connection file (usually config.php or db_connect.php) with your DB credentials, browse to the project URL in your browser.
How do I set up the database for this PHP project?
Open phpMyAdmin (http://localhost/phpmyadmin/ on XAMPP), create a new empty database with the name specified in the project’s config.php. Click the Import tab, choose the included .sql file, click Go. Then edit config.php (or includes/connection.php) with: ‘localhost’, your MySQL username (usually ‘root’), your MySQL password (usually blank for XAMPP), and the database name.
Can I use this PHP project for a BSIT capstone or thesis?
Yes, but extend it. A bare CRUD app is too narrow for full capstone scope. Add: user roles via session checks, reports/dashboards (Chart.js + AJAX), PDF exports (TCPDF library), email notifications (PHPMailer), real domain extension (analytics, audit log, multi-branch support). Pair with Chapter 1-5 documentation matching your panel’s rubric.
Why am I getting ‘connection error’ or ‘undefined function mysqli_connect’?
Three common PHP issues: (1) Connection error: Apache + MySQL services not running in XAMPP control panel, OR database name in config.php does not match what you created in phpMyAdmin. (2) ‘undefined function mysqli_connect’: MySQL extension not enabled, in php.ini uncomment extension=mysqli (then restart Apache). (3) ‘No such file or directory’: MySQL socket path wrong, use 127.0.0.1 instead of localhost in the connection string.
Where can I find more PHP projects with source code?
Browse the PHP Projects hub for the full library (300+ vanilla PHP systems). For modern PHP MVC alternatives see Laravel Projects (74 systems) or CodeIgniter Projects (32 systems). For BSIT-focused capstone idea lists see 150 Best Capstone Project Ideas.
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Joken E. Villanueva
Founder & Lead Developer at PIES IT Solution
Founder of PIES Information Technology Solutions, a software company building production-grade applications for institutions across the Philippines. Over 8 years of hands-on full-stack development experience, currently leading the development of ClinicAI, an AI-powered clinic management platform.
Expertise: PHP · MySQL · JavaScript · AI Integration · SaaS Architecture · VB.NET · Database Design · Capstone Documentation · Java · View all posts by Joken E. Villanueva →