Find the closest number to value not working (SQL)

Question

I have the following SQL Command:

$sql = "SELECT TOP 1
        FROM products
        ORDER BY ABS( price - '$price' ) ASC LIMIT 1";

$result = $conn->query($sql);


while($row = $result->fetch_array()){
    echo "\r\n";
    echo $row['price'];
    echo "\r\n";
} 

What I want to do is to find the closest number in column "price" to local variable $price. For example when user input price is 15000 I want to find closest number to this in the "price" column of the products table. Unfortunatly that gives me this problem:

PHP Fatal error:  Uncaught Error: Call to a member function fetch_array() on bool in C:\Users\rojto\Documents\clones\Techalo\techalo-improvements\database.php:25
Stack trace:
#0 {main}

Can someone help me please?

Answer 1

You should have a column name in the SELECT clause instead of TOP 1 .

Presumably, you want:

SELECT price
FROM products
ORDER BY ABS(price - :price) 
LIMIT 1;

Note that this uses query parameter to pass the target price value rather than concatenating it into the query string. You can have a look at this famous SO post to learn why and how to avoid SQL injection.