Why Does `mysqli_fetch_array()` Return \'expects parameter 1 to be mysqli_result, boolean given\' When Checking for Duplicate Data?

mysqli_fetch_array() Error When Checking for Duplicate Data

When attempting to determine if a Facebook User_id exists in a database, users may encounter the error: "mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given."

Analysis

This error indicates that the mysqli_query() function, which executes the database query, is failing and returning false. As a result, mysqli_fetch_array() is unable to retrieve the expected result set from the query.

Solution

To troubleshoot the issue, insert the following code after the mysqli_query() call:

if (!$check1_res) {
    trigger_error(mysqli_error($con), E_USER_ERROR);
}

This code displays the MySQL error message associated with the failed query, providing insights into the underlying cause of the problem.

Additional Information

For more detailed documentation on the mysqli_error() function:

• [PHP Manual: mysqli_error()](http://www.php.net/manual/en/mysqli.error.php)

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