Re: SQL - histogram

From: "Txugo" <msalt@uol.com.br>

> I have a table where one record represent a person, including his height.
> I'd like to know how many person have more than 150 cm, more than 160 cm
> and so on.
> How can I do that using SQL?
>
> Example:
> people > 150 - 1000
>        > 160 -  850
>        > 170 -  500
>        > 180 -  200
>        > 190 -  30
> thanks in advance

richardh=> select * from people;id | height
----+-------- 1 |    150 2 |    155 3 |    160 4 |    165
(4 rows)

richardh=> select * from heights;cm
-----150160
(2 rows)

richardh=> select cm,count(id) from people, heights where height>=cm group
by cm;cm  | count
-----+-------150 |     4160 |     2
(2 rows)

HTH

- Richard Huxton