MySQL_Connect Function: The Complete Guide to MySQL_Connect()
When working with any database management system (DBMS), a way must exist to access the said database. And with MySQL database, the MySQL_Connect function is provided for easy access and connection to a MySQL database.
Notably, let’s be clear; you can’t just access a MySQL database without opening a connection. Such a connection can be non-persistent and opens the door for you to get inside and interact with the database.
So let’s dive in and gain more insight and understanding on dealing with connections in a MySQL database environment.
What Is MySQL_Connect?
As we’ve alluded above, a connection is required to access a MySQL database. And the MySQL_Connect() function is provided solely for this purpose. Once you call the function in your application, it opens a non-persistent connection to the specified MySQL database.
If the connection to the database was successful or TRUE, the connection is returned, and you can begin interacting with the database. On the other hand, if the connection was unsuccessful or FALSE, you’ll get an error message informing you accordingly.
Now, let’s take a look at the syntax for using the MySQL_Connect() function properly:
As can be observed from the above syntax, the function takes on three parameters:
1. Hostname: The hostname indicates the server where the database is located. This parameter is also known as servername. It’s an optional parameter and can also include the specific port number the MySQL database is listening (for example “hostname:3306”).
2. Username: The connection can also take on the username parameter which indicates the user with access to the database.
3. Password: Next, the connection needs the user’s password, which is passed on with this parameter.
4. Database Name Finally, you need to specify the name of the database you are trying to connect.
Another critical point to remember is that the database connection established with this function is non-persistent. And this means that the database connection closes once the script completes its task.
What Is Persistent Database Connection?
A persistent database connection is a SQL connection to a database that does not close when the execution of the script ends.
Whenever you establish a persistent database connection, there’s a check to ensure that an identical persistent connection (i.e., one opened prior) does not exist. If one already exists, a new connection will not open but rather the existing one used.
The MySQL_Connect() is a non-persistent database connection function. If you want to establish a persistent database connection, then you must use the MySQL_PConnect() function.
How PHP Works with MySQL_Connect()
As one of the most popular open-source databases in the world, MySQL is often used as part of the LAMP stack. LAMP stands for Linux Apache MySQL and PHP.
So it’s right to say that must of the users of MySQL database is using it within their PHP web application. Of course, users of other programming languages such as Python, Ruby, ASP.NET, etc. equally use MySQL.
Now, from a PHP perspective, you can connect your PHP website or application to a MySQL database using the PHP MySQL Connect function accordingly.
PHP MySQL_Connect() Syntax
Here’s what the syntax looks like when establishing a database connection using PHP MySQL_Connect() function:
<?php $mysql = new mysqli("hostname", "username", "password", "databasename"); ?>
If you’re connecting to a local database that is on the same server as the PHP website, then the hostname parameter will be localhost.
Then you can simply provide the username, password and databasename parameters to establish a database connection.
What Does MySQL Connect Return
Once you successfully (i.e., TRUE) connection to the MySQL database using this function, the function returns MySQL link identifier object if the connection was successful. However, if the connection was unsuccessful (i.e., FALSE), the function returns a failure error message which you catch and handle appropriately.
MySQL_Connect vs MySQLI_Connect
With this in mind, you may have come across the MySQLI_Connect function and rightfully wondering what’s the difference between it and the MySQL_Connect function.
So let’s address this difference and discuss it a little bit more.
What Is The Difference Between MySQL_Connect and MySQLI_Connect?
The MySQLI_Connect() function is an improved version of the MySQL_Connect() function. The i stands for improved. MySQLI_Connect is more secure and provides many features and benefits which the previous one does not such as:
1. It supports prepared statements
2. Provides procedural and object-oriented interfaces
3. Transactions can be run through API
4. Support stored procedures
5. Enhanced security and improved debugging facilities
What Does MySQLI_Connect Return?
As with its predecessor, the MySQLI_Connect function returns a link identifier object if the connection was established successfully. A successful connection allows you to access and interact with the database. If the connection failed, then it will throw an error and return a failure message.
How To Change MySQL to MySQLI?
If you’re considering changing from MySQL to MySQLI the first and easiest thing to do is replace the mysql in your code to mysqli.
So for example:
1. mysql_connect will become mysqli_connect
2. mysql_query will become mysqli_query
3. mysql_error will become mysqli_error
..and so on.
Of course, the above is a simplistic approach on how to change MySQL to MySQLI. Furthermore, you must check all parameters of the different function calls in your code to make sure any differences are addressed.
Is MySQL_Connect Deprecated?
Yes, the creative minds at PHP.net have deprecated the MySQL_Connect() function since PHP 5.5 and it’s no longer supported as of PHP 7. So it’s highly recommended that everyone starts using the new MySQLI_Connect() function.
With the deprecated MySQL_Connect() function, PHP now provides the MySQLI_Connect() function as a replacement.
Why Is MySQL Connect Deprecated?
MySQL_Connect() was deprecated to provide an improved and more secure way of establishing connections to a MySQL database. The benefits of the new function are many as outlined above.
MySQL_Connect Deprecated Replacement
Upon deprecating the MySQL_Connect() function, PHP provided the MySQLI_Connect() function as a reliable and improved replacement.
Now, let’s look at other usage consideration for this function.
Dealing With Dreaded “WARNING MySQL_Connect” Error Message
When working with MySQL database, you’ll eventually encounter the warning mysql_connect error message at one point or the other. However, do not be alarmed as this is merely telling you that there was an issue with your connection call, and it didn’t go successfully.
Therefore, first of all, check to make sure that your connection parameters are correct. You can do this by making sure you’re connecting to the right database by looking at the hostname specified. In most case, you should use localhost as the hostname.
Then you need to ensure that the databasename provided as well as username and password are accurate. Also, make sure that the user you’re connecting with has the appropriate privileges to the database.
Handling “MySQL_Connect Not Working” Situations
Whenever you encounter the mysql_connect not working error message, the first thing you should do it to check which PHP version you’re working with.
If you’re working with PHP 7, then remember that the MySQL_Connect() function is no longer supported in PHP 7. And in such instance, you need to use the MySQLI_Connect() function instead.
Working with MySQL_Connect on LocalHost
Most times, you’ll be working on a local environment (i.e., your computer) and need to be able to connect to a MySQL database to test things out.
You need to specify your hostname as localhost in your connection parameters. And if you’re trying to figure out how to connect to MySQL on Windows then you use the IP address 127.0.0.1 in place of the localhost parameter value.
And remember, as we’ve mentioned above, you may also need to indicate the port number in your MySQL_Connect() function.
In conclusion, we hope that this article has added more to your knowledge of this essential MySQL function and how to best work it. Feel free to read more about the function online and let us know what you think.