Re: SQL Query gone wrong.. please help

On 9 Feb 2006, at 12:08, Srinivas Iyyer wrote:

> Dear group,
>
> I have three tables:
>
>
> table: sequence
> seq_id | seq_name | seq_refseq
> 1 | EI24 | NM_004879.3
> 2 | NDRG2 | NM_201540.1
> 3 | RARRES2 | NM_002889.2
>
>
>
> table: gos
> gos_id | go_id | go_term | go_class
> 11041 | GO:0006807 | nitrogen compound metabolism |P
> 11049 | GO:0004263 | chymotrypsin activity| F
>
> table : go_seq
>
>
> gos_id | seq_id
> 13819 | 11408
> 13819 | 11950
> 13819 | 12822
> 13819 | 11350
>
>
>
>
> I want to query go_seq table, giving seq_name = 'EI24'
>
>
> select seq_name, go_term
> from sequence, gos, go_seq
>
>
> where go_seq.seq_id = go_seq.gos_id and
> sequence.seq_id = sequence.seq_name and
> sequence_seq_name = 'EI24';
>

you are not joining over the relationship table (go_seq) correctly.
you want:

WHERE
sequence.seq_name = 'EI24' AND
sequence.seq_id = go_seq.seq_id AND
go_seq.gos_id = gos.gos_id;

what you previously had was wrong in two locations:
"sequence.seq_id = sequence.seq_name" (i assume no sequence ID will
ever be quite like it's name) and
"go_seq.seq_id = go_seq.gos_id" (i assume no GO id will have the same
ID as a sequence).

>
> I am wrong here, unable to get it correctly. Could
> you please help here.
>

unfortunately (by the looks of your query), your understanding of SQL
is fundamentally flawed, which will lead to future confusion and
trouble. i'd recommend picking up a decent book on SQL, or checking
out some online tutorials.

> thanks
> srini

hope that helped a bit!

murat