Question

This query works fine when I call it in in my php page without surrounding it with a function and a name

//MAKE DATABASE CALL TO GET PRODUCT 
$product_id = $line_value['productId'];
$product_query = "SELECT * 
                  FROM products
                  WHERE id = '$product_id'
                  LIMIT 1";
$product_result = pg_query($con, $product_query);
while ($product_row = pg_fetch_assoc($product_result)){
    $product = $product_row['product'];
}
//works
echo $product;

But I get an error when I try to put it within a function

$product = _get_product($product_row['product']);
echo $product'

function _get_product($product_id){

//prints 1
echo $product_id
    //MAKE DATABASE CALL TO GET PRODUCT 
    $product_id = $line_value['productId'];
    $product_query = "SELECT * 
                      FROM products
                      WHERE id = '$product_id'
                      LIMIT 1";
    $product_result = pg_query($con, $product_query);
    while ($product_row = pg_fetch_assoc($product_result)){
        $product = $product_row['product'];
    }

return $product;

}

Warning: pg_query() expects parameter 1 to be resource, null given in
/home/www.site.com/file.php on line
263

I thought perhaps that the function didn’t have access to the included db connection file at the top of the page, but when I put that within the function, I got this error

Warning: pg_query() [function.pg-query]: Query failed: ERROR: invalid
input syntax for integer: “” LINE 3: WHERE id = ” ^ in
/home/www.site.com/file.php on line 265

What have I done wrong? Thanks!

Answer 1

The issue is variable scope. The scope of the function does not include variables declared outside of it.
Don’t use global variables, instead allow the function access by passing $con as a parameter:

function _get_product($product_id, $con){

And use this to call it:

 _get_product($line_value['productId'], $con);