Prevent Saving Duplicate Data To Database

[IkkeEnGij]

it will always succeed,even if there is nothing to insert
the database.execute method fails silently, unless you tell it to report the error
if you want it to return an error if it fails, you have to call it like:

CurrentDb.Execute S,dbFailOnError

and trap the error

https://msdn.microsoft.com/en-us/lib...ffice.12).aspx