Search returning multiple results based on database foreign key table
I've added an 'industryID' column to an existing tablethat had foreign keys for product ID and lubricant ID already. This will allow products to be categorized by both lubricant and industry (see mysqlTable.jpg file).
Each product has multiple lubricants (for example, it may be classified as both an industrial oil and a gear oil) and multiple industries. In the table, there may be several records which show the same product number (PN) key and lubricant (L) key, but different industry (I) keys [(PN) 200, (L) industrial oil, (I) agriculture, marine, construction).
This works fine except on searches by product number or lubricant, which don't filter out the industry, returning results like: (PN) 200, (L) industrial oil, industrial oil, industrial oil (see Search.jpg file). It's ok if the results show more than one product for each lubricant, but how can I get it to stop showing multiple results based on the added industry column?
The search is online, but the latest industry page is not, so I've included screen shots along with files.