使用if语句打开DUPLICATE KEY UPDATE

Question

I need to import data from two csv files.

If the second file contain same sku it should only update if price is lower than price exist.

Here is my code:

$sql = mysql_query("INSERT INTO varer (sku,productname,price,mpn,stock,distributor)  

VALUES ('$sku','$productname','$price','$mpn','$stock','$distributor')"); 

Above code works fine for just inserting data so problem is only if same sku will be there.

Here is what i want to do:

If $SKU exists in database and $price is lower than price exist in database it should update $price, $productname, $stock, $distributor

Please let me know if you have any suggestions.

Answer 1

From the docs

INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6)
  ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);

Seems like the original colum is available under its name, and the values to be inserted need the VALUES() function. Updating to the max of new and old price should be easy: How to get the max of two values in MySQL?