On Tue, Jan 20, 2004 at 05:15:15PM -0500, jim wrote:
> if they already have these constraints at the column level,
> why do they need them a second time as in ...
> name [type] [[CONSTRAINT name] column-constraint]*
Because you may want a composite primary key or set of unique columns. A
simple example is
CREATE TABLE person (
person_id INTEGER PRIMARY KEY
lastname TEXT,
firstname TEXT,
UNIQUE (lastname, firstname)
);
Dave Cook
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