PHP | mysqli_connect_error() Function

PHP mysqli_connect_error() Function


Hello folks! welcome back to another edition of our tutorial on PHP. In this tutorial guide, we are going to be discussing about the PHP mysqli_connect_error() Function.

During the attempt to connect to MYSQL server, if any error occurs the built-in PHP mysqli_connect_error() function returns the description of the error occurred (during the last connection call).

Syntax

Following below is the syntax to use this function -

mysqli_connect_error()


Parameter Details

This PHP function does not accept any parameters.

Return Value

This built-in PHP function returns a string value representing the description of the error from the last connection call, Incase of a failure. If the connection was successful, this function returns NULL.

PHP Version

This built-in PHP function was first introduced in PHP version 5 and works in all the later versions.

Example1

The following below is an example which demonstrates the usage of PHP mysqli_connect_error() function (in a procedural style) -

<?php
   //Creating a connection
   $con = @mysqli_connect("localhost", "root", "wrong_password", "mydb");

   //Connection Error
   $error = mysqli_connect_error($con);
   print("Error: ".$error);
?>

Output

When the above code is executed, it will produce the following result -

Error: Access denied for user 'root'@'localhost' (using password: YES)

Example2

In an object oriented style the syntax of this function is $con->connect_error(). Following is the example of this function in an object oriented style $minus;

<?php
   //Creating a connection
   $con = @new mysqli("localhost", "root", "wrong_password", "mydb");

   //Connection Error
   $error = $con->connect_error;
   print("Error: ".$error);
?>

Output

When the above code is executed, it will produce the following result -

Error: Access denied for user 'root'@'localhost' (using password: YES)

Example3

The following example demonstrates the behaviour of PHP mysqli_connect_error() function Incase of a successful connection -

<?php
   //Creating a connection
   $con = @mysqli_connect("localhost", "root", "password", "mydb");
   
   //Connection Error
   $error = mysqli_connect_error();
   if(!$con){
      print("Connection Failed: ".$error);
   }else{
      print("Connection Established Successfully");
   }
?>

Output

When the above code is executed, it will produce the following result -

Connection established successfully

Example4

Try the following example below -

<?php
   $connection = @mysqli_connect("localhost","root","wrong_pass","wrong_db");
   
   if (!$connection){
      die("Connection error: " . mysqli_connect_error());
   }
?>

Output

When the above code is executed, it will produce the following result -

Connection error: Access denied for user 'root'@'localhost' (using password: YES)


Alright guys! This is where we are rounding up for this tutorial post. In our next tutorial, we will discuss about the PHP mysqli_debug() Function.

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