@UNQREADS[[u,]filename,"key"] : Read a value from an existing key in an UnQLite database.
|u||Optional flag that the key is Unicode (UTF16)|
|filename||Database opened with @UNQOPEN|
|key||Key to read|
Returns the value as a string, or the error text. If the key doesn't exist (or doesn't have a value) @UNQREADS will not display anything.