PHP | mysqli_connect_errno() Function

PHP mysqli_connect_errno() 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_errno() Function.

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

Syntax

Following below is the syntax to use this function -

mysqli_connect_errno()


Parameter Details

This PHP function does not accept any parameters.

Return Value

This built-in PHP function returns an integer value representing the code of the error from the last connection call, Incase of a failure. If the connection was successful, then this function returns 0.

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_errno() function (in a procedural style) -

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

   //Client Error
   $code = mysqli_connect_errno();
   print("Error Code: ".$code);

Output

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

Error Code: 1045

Example2

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

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

   //Error code
   $code = $con->connect_errno;
   print("Error Code: ".$code);
?>

Output

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

Error Code: 1045

Example3

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

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

   //Error Code
   $code = mysqli_connect_errno();
   if($code){
      print("Connection Failed: ".$code);
   }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_errno());
   }
?>

Output

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

Connection error: 1045


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

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