Can i create unique item transaction default locator via personalisation

hi

i am looking to create a personalisation to make the item transaction default locator unique i.e. only 1 inventory item per locator

i have tried unsuccessfully so far using an SQL type query to implement the requirement

my thoughts are that i can create a warning message when a new value being entered into the stock locator is equal to one that already exists

Example

Item A Receiving Locator = A.A.1.1

New Item

Item B Receiving Locator = A.A.1.1 (error message - locator is not unique please enter a new value)

Thanks

Mark