How can I check for duplicate SQL queries in a simple loop that creates SQL queries?

[rs2k]

I have a loop of code that creates SQL queries from a CSV file. Below is a very simplified version of the loop:

   $fh = fopen($outfile, "r");

   while (list($model, $quantity) = fgetcsv($fh, 1024, ",")) {

    $sql = "update products p set p.products_quantity = '" . $quantity . "' where p.products_mfgmn = '" . $model . "'";

 tep_db_query($sql);

}

The problem is that the csv file has over 80,000 lines and many of the lines have multiple entries for $model. The CSV file may have 50 entries while the MySQL database may have 500 entries for the $model. This means a query that updates 500 entries will be run 50 times which makes this code EXTREMELY inefficient and slow. Is there a way to make sure only one of each SQL runs. I bet there is a fairly simple way to do it, but I'm still very new to PHP.

[NogDog]

You could do something like the following, perhaps:

$modelsUpdated = array();
while (list($model, $quantity) = fgetcsv($fh, 1024, ",")) {
   if(isset($modelsUpdated[$model]))
   {
      continue;
   }
   $modelsUpdated[$model] = 1;
   // continue processing this record....
}

[Weedpacket]

Or a slight variation:

while(list($model,$quantity)=fgetcsv($fh,1024,","))
{
    $quantities[$model] = $quantity;
}
foreach($quantities as $model=>$quantity)
{
  // Update the record
}

[rs2k]

Thank you very much!

I will try those out and report back with the results.