Finding/searching for missing values in MySQL

Question

I am using MySQL and have a table called sales. Its primary key is sales_id.

-------------------------------------
sales_id | invo         


        

Answer 1

As you are searching for invoice_id then make sure you have an index on that column. otherwise queries will be slow.

You can try the following code

$inv_ids=range(147,4497);
$str_inv_ids=implode(",",$inv_ids);
$query="SELECT DISTINCT invoice_id FROM sales WHERE invoice_id IN ($str_inv_ids)";
$result=mysql_query($query);

while ($row = mysql_fetch_assoc($result)) {
    $inv_ids_db[]=$row['invoice_id'];
}
// It gives invoice Ids that are in $inv_ids but not in $inv_ids_db
$missing= array_diff($inv_ids,$inv_ids_db); 

print_r($missing);