[sqlite] Multicolumn unique (resending)

[Richard Hipp]

On 2/24/16, Klaus Jantzen <k.d.jantzen at mailbox.org> wrote:
> Hello,
>
> after reading the SQLite documentation I decided to change some of my
> database
> applications to use SQLite.
>
> Following the syntax descriptions and after some experiments I found out
> that one cannot
> define a multicolumn constraint   ... UNIQUE(col_a, col_b, col_c).
>
> How would you do that in SQLite?

It is done in SQLite as in all other SQL database engines, using a
table constraint.  Like this:

   CREATE TABLE t1(a,b,c,d,UNIQUE(a,b,c));

Note the comma before the UNIQUE keyword.

-- 
D. Richard Hipp
drh at sqlite.org