So they were null, and null turns out to be a seven-character blank string!?
Btw, you can change the displayed value of null with
\pset null nil
and you will seem 4+ million 'nil's in your output
Tena Sakai wrote:
Hi Osvaldo,
> Try:
> SELECT count(*) FROM gallo.sds_seq_reg_shw;
> SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NULL;
> SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NOT NULL;
> Don't use count(maf), use count(*).
Indeed!
canon=# SELECT count(*) FROM gallo.sds_seq_reg_shw;
count
---------
4645647
(1 row)
canon=# SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NULL;
count
---------
4578363
(1 row)
canon=# SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NOT
NULL;
count
-------
67284
(1 row)
$ dc
4578363 67284 + p q
4645647
$
Many thanks, Osvald.
Regards,
Tena Sakai
tsa...@gallo.ucsf.edu
-----Original Message-----
From: Osvaldo Kussama [mailto:osvaldo.kuss...@gmail.com]
Sent: Tue 6/30/2009 6:49 PM
To: Tena Sakai
Subject: Re: [SQL] it's not NULL, then what is it?
2009/6/30 Tena Sakai <tsa...@gallo.ucsf.edu>:
> Hi Everybody,
>
> I have a table called gallo.sds_seq_reg_shw,
> which is like:
>
> canon=# \d gallo.sds_seq_reg_shw
> Table "gallo.sds_seq_reg_shw"
> Column | Type | Modifiers
> ------------------+---------+-----------
> name | text |
> response | text |
> n | integer |
> source | text |
> test | text |
> ref | text |
> value | real |
> pvalue.term | real |
> stars.term | text |
> gtclass.test | text |
> fclass.test | text |
> gtclass.ref | text |
> fclass.ref | text |
> markerid | integer |
> maf | real |
> chromosome | text |
> physicalposition | integer |
> id | text |
> ctrast | text |
>
> I am intereseted in the column maf (which is real):
>
> canon=# select maf from gallo.sds_seq_reg_shw
> canon-# order by maf asc;
> maf
> -------------
> 0.000659631
> 0.000659631
> 0.000659631
> 0.000659631
> .
> (trunacated for the interest of breivity)
> .
>
> Another way to look at this column is:
>
> canon=# select maf from gallo.sds_seq_reg_shw
> canon-# order by maf desc;
> maf
> -------------
>
>
>
> .
> (trunacated for the interest of breivity)
> .
>
> These rows shown are blanks, as far as I can tell.
> But...
>
> canon=# select count(maf) from gallo.sds_seq_reg_shw;
> count
> -------
> 67284
> (1 row)
>
> canon=# select count(maf) from gallo.sds_seq_reg_shw
> canon-# where maf ISNULL;
> count
> -------
> 0
> (1 row)
>
> canon=#
> canon=# select count(maf) from gallo.sds_seq_reg_shw
> canon-# where maf NOTNULL;
> count
> -------
> 67284
> (1 row)
>
> My confusion is that if they are real and not null,
> what are they? How would I construct a query to do
> something like:
>
> select count(maf)
> from gallo.sds_seq_reg_shw
> where maf ISBLANK;
>
Try:
SELECT count(*) FROM gallo.sds_seq_reg_shw;
SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NULL;
SELECT count(*) FROM gallo.sds_seq_reg_shw WHERE maf IS NOT NULL;
Don't use count(maf), use count(*).
Osvaldo
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