Efficient Table and CSV merging

[wxdqz]

I have got to merge a csv into a table which holds about 300,000 records. The CSV will approximately hold about 3000 changes for these records to be made.

I basically need to match primary keys and update a table field with a value(s) from the CSV file for that record.

I have mySQL PHP and ASP available.

Any suggestions to the best language - and best method to complete this ?

Thanks