[EMAIL PROTECTED] wrote: > On Tue, 17 Oct 2000, Matthew Kennedy wrote: > > Is it possible to perform an alter table with add foreign key constraint > > in PostgreSQL? We are trying to support multiple DBMS in our project by > > keeping to a common, compatible denominator. Oracle, supports such a > > construct. Does (or might) PostgreSQL support this feature? > Yes... > ALTER TABLE <table> ADD <constraint definition> > Brett W. McCoy Firstly... A little redefinition of my question is in order. If I try doing this: create table things (name varchar(20), state(2)); create table states (abbreviation varchar(2)); alter table things add foreign key (state) references states (abbreviation); Postgres responds with: NOTICE: ALTER TABLE ... ADD CONSTRAINT will create implicit trigger(s) for FOREIGN KEY check(s) CREATE I am wondering what the implications of postgres using implicit triggers for foreign key constraints are? I guess if there were no implications (ie. implicit triggers were a perfect implimentation of foreign keyt constraints), then there would be no warning message? Secondly... Postgres doesn't seem to take the name of a foreign key (it's a parse error to include it). This is slightly different to what SQL92 and Oracle allow. I beleive I should have been able to write: alter table things add foreign key things2states (state) references states (abbreviation); Postgres responds with: ERROR: parser: parse error at or near "things2states" I don't really need postgres to do anything with the name of the foreign key. I would like it to ignore it, rather than bawk at it. (I'm trying to feed the output of a relational design tool to PostgreSQL without having to write too many filters to strip out things postgres doesn't like). Perhaps I just have the syntax wrong? Thanks and much appreciated, Matt