>The documentation seems to say that I can set a 1 to 1 relationship between tables with the command "Alter Table table1 references table2". However this gives me a syntax error, as does "alter table table1 references table2 tag mytag". Can anyone tell me what the syntax of the command to establish a 1 to 1 relationship between 2 tables with primary keys in a DBC? Thanks.

The References keyword seems to only work with a Foreign Key clause, however, since mytag is already the primary key, it will simply add the reference and not overwrite the tag or create another one. This should work (at least, it did for me):

Alter Table table1 Add Foreign Key Tag mytag References table2 Tag mytag