Mysqli_Num_Rows() Expects Parameter 1 To Be Mysqli_Result

While working with PHP and MySQL, we come across an error called mysqli_num_rows() expects parameter 1 to be mysqli_result. We will take a closer look at this error in this article.  

Error Code 1

$dbcon = mysqli_connect("localhost", "root", "", "databasename");

if (!$dbcon) {
  die("Connection failed: " . mysqli_connect_error());
}
$resultAll = mysqli_query($dbcon, "SELECT * FROM employee");
if(!$resultAll){
	die(mysqli_error($dbcon));
}
if (mysqli_num_rows($resultAllNEW) > 0) {
	while($rowCatData = mysqli_fetch_array($resultAll)){
		echo $rowCatData["employee_name"].'<br>';
	}
}

Output:

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result

Explanation 

In the code, you can check that the result stored in the variable $resultAll is not passed correctly. It is necessary that you assign the result properly to this variable before passing it to the mysqli_num_rows method.       

Error Code 2

mysqli_num_rows($resultAllNew)

Correct Code

mysqli_num_rows($resultAll)

Explanation 

The code above runs perfectly as we have stored the result in the variable $resultAll.

Correct Code

$dbcon = mysqli_connect("localhost", "root", "", "databasename");

if (!$dbcon) {
  die("Connection failed: " . mysqli_connect_error());
}
$resultAll = mysqli_query($dbcon, "SELECT * FROM employee");
if(!$resultAll){
	die(mysqli_error($dbcon));
}
if (mysqli_num_rows($resultAll) > 0) {
	while($rowCatData = mysqli_fetch_array($resultAll)){
		echo $rowCatData["employee_name"].'<br>';
	}
}