Question

I’m looping through a CSV to insert/update the name field of some records into a table. The script is mean’t to insert the record and if it exists, only update the name field.

It’s taking quite some time for larger CSV files so I was wondering if this code could be modified into a multiple INSERT query with an ON DUPLICATE KEY UPDATE command which will only update the name field of the record.

The CSV DOES NOT contain all the fields for the table, only the ones for the primary key and the name. And for that reason, REPLACE will not work for this case.

if (($handle = fopen($_FILES['csv']['tmp_name'], "r")) !== FALSE) {
        while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
            $title = 'Import: '.date('d-m-Y').' '.$row;

            # CHECK IF ALREADY EXISTS
            $explode = explode('-',$data[0]);
            $areacode = $explode[0];
            $exchange = $explode[1];
            $number = $explode[2];

            $update = "INSERT INTO ".TBLPREFIX."numbers SET
            area_code = ".$areacode.",
            exchange = ".$exchange.",
            number = ".$number.",
            status = 1,
            name = '".escape($data[1])."'
            ON DUPLICATE KEY UPDATE name = '".escape($data[1])."'";
            mysql_query($update) or die(mysql_error());
            $row++;


        }
        fclose($handle);
        $content .= success($row.' numbers have been imported.');
    }

Answer 1

Open a transaction before you start inserting, and commit it after you are done. This way the database can optimize the write operation on disk, because it takes place in a separate memory space. Without a transaction, all single queries are automatically committed at once and effective for every other query.

At least I hope you are using InnoDB as a storage engine – MyISAM does not support transactions and has other significant drawbacks. You should avoid it if possible.