On Mon, May 11, 2020 at 9:56 AM Peter Devoy <pe...@3xe.co.uk> wrote: > I need to store addresses for properties (as in real estate) so in my > naivety I created a unique constraint like this: > > ALTER TABLE properties > ADD CONSTRAINT is_unique_address > UNIQUE ( > description, --e.g. Land north of Foo Cottage > address_identifier_general, > street, > postcode > ); > >
> Please can anyone recommend a way of approaching this? Perhaps empty > strings > are pragmatic in this situation? > Don't add a unique table constraint (aside from an artificial primary key). Then, if you can define a problem where you feel having a unique table constraint over the field is the correct solution - especially given the fact that you can have missing data in the relevant fields - you should post the problem and take suggestions on ways to solve it. David J.
