Disable possibility to enter two prices for the same item

Tiwaz

Hi everyone
I have a bit of dillema here.
How can I control that a client cannot enter two different prices for the same Item.
Ex.: If the Item is Bicycle and it's code is 1001, and the price is 1234.9$, how can I stop someone from entering that same Item but with different price.
Thank you so much

mohana_cse06

You need to add primary key of the table with Item No. only

Tiwaz

Oh, sorry, I forgot to write that every Item has it's date in my table. So it is possible to have few same items but with different date. I want to prevent people from entering same Item with the same date with differrnt price

mohana_cse06

again, check table 7002 for reference.
if you have only those 2 fields then you can add item No and Date field in primary key