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; Thank you in advance. Regards, Tena Sakai tsa...@gallo.ucsf.edu