SELECT COUNT(*) AS count - How to use this count

Instead of doing:

$cars = $mysqli->query("SELECT * FROM cars"); $count = $cars->num_rows(); if ($count) { // is rows } 

I want to not have to select all rows or a single column, I simply want the count.

In my head:

$cars = $mysqli->query("SELECT COUNT(*) as count FROM cars"); 

But then how do I use that count value? I need to run an if statement on it.

5 Answers

It's not recommended to use reserved words for names in SQL. So I call the count result cnt instead. As your function is scalar, i.e. you expect only one value back, you can use:

$count = $mysqli->query("select count(*) as cnt from cars")->fetch_object()->cnt; 

Select queries always return a resultset. To take the count, use fetch_row()

$result = $db->query("SELECT COUNT(*) FROM `cars`"); $cars= $result->fetch_row(); echo '#: ', $cars[0];// or use $c= $cars[0]; 

You need to get first row of your result and see the 'count' column value:

$cars = $mysqli->query("SELECT COUNT(*) as count FROM cars"); $firstrow = $cars->fetch_assoc(); if ($firstrow['count'] > 0) { // ... } 

If result is an object then:

$cars = $mysqli->query("SELECT count(*) as count FROM cars"); $carRows = $cars->result(); echo $carRows[0]->count; 

If you return array then:

$cars = $mysqli->query("SELECT count(*) as count FROM cars"); $carRows = $cars->result_array(); echo $carRows[0]['count']; 

You have many options available to get the count from SQL.

If you are already on PHP 8.1, the simplest is this:

$count = $mysqli->query("SELECT COUNT(*) FROM cars")->fetch_column(); 

Here is a list of other possible methods:

• Using associative array:

$count = $mysqli->query("SELECT COUNT(*) as count FROM cars")->fetch_array()['count']; 

• Using numerical array:

$count = $mysqli->query("SELECT COUNT(*) FROM cars")->fetch_array()[0]; 

• Using an object notation

$count = $mysqli->query("SELECT COUNT(*) as count FROM cars")->fetch_object()->count; 

Important point. If you need to use variable input in your query then you should use prepared statement. To get the count then it would look like this:

$stmt = $mysqli->prepare("SELECT COUNT(*) FROM cars WHERE category=?"); $stmt->bind_param('s', $category); $stmt->execute(); $count = $stmt->get_result()->fetch_row()[0];