Re: data integrity and inserts

From: Scott Frankel <leknarf(at)pacbell(dot)net>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: data integrity and inserts
Date: 2004-12-01 18:48:40
Message-ID: 9E3F9598-43C9-11D9-9E72-000A95A7B782@pacbell.net
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1.
CREATE TABLE names (the_id SERIAL PRIMARY KEY, the_name text);
CREATE UNIQUE INDEX uidx_thename ON names(the_name);

vs.

2.
CREATE TABLE names (the_id SERIAL PRIMARY KEY, the_name text UNIQUE);

Is the UNIQUE constraint in the second solution merely short-hand for
the explicit
index declaration of the first solution? Or is there a functional
difference between
them that I should choose between?

Thanks again!
Scott

On Dec 1, 2004, at 10:11 AM, Scott Frankel wrote:

>
> I want to ensure data integrity when inserting into a table,
> preventing multiple
> entries of identical rows of data.
>
> Does this call for using a trigger?
> How would triggers perform a query to test if data already exists in
> the table?
>
> (The doco outlines how triggers perform tests on NEW data inserted
> into a
> table; but I haven't found anything on data already extant.)
>
> Thanks in advance!
> Scott
>
>
> sample table:
>
> CREATE TABLE names (the_id SERIAL PRIMARY KEY, the_name text);
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster
>

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