Re: combine SQL SELECT statements into one
От | msi77 |
---|---|
Тема | Re: combine SQL SELECT statements into one |
Дата | |
Msg-id | 6951265019068@webmail103.yandex.ru обсуждение исходный текст |
Ответ на | combine SQL SELECT statements into one (Neil Stlyz <neilstylz@yahoo.com>) |
Ответы |
Re: combine SQL SELECT statements into one
|
Список | pgsql-sql |
Hi, SELECT (SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-02-01') as count1, (SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-01-20') as count2, (SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-01-01') as count3 Serge > Good Evening, Good Morning Wherever you are whenever you may be reading this. > I am new to this email group and have some good experience with SQL and PostgreSQL database. > I am currently working on a PHP / PostgreSQL project and I came upon something I could not figure out in SQL. I was wonderingif anyone here could take a look and perhaps offer some guidance or assistance in helping me write this SQL query. > Please Consider the following information: > ------------------------------------------- > I have a postgresql table called 'inventory' that includes two fields: 'model' which is a character varying field and 'modified'which is a timestamp field. > So the table inventory looks something like this: > model modified > ------------- ---------- > I778288176 2010-02-01 08:27:00 > I778288176 2010-01-31 11:23:00 > I778288176 2010-01-29 10:46:00 > JKLM112345 2010-02-01 08:25:00 > JKLM112345 2010-01-31 09:52:00 > JKLM112345 2010-01-28 09:44:00 > X22TUNM765 2010-01-17 10:13:00 > V8893456T6 2010-01-01 09:17:00 > Now with the table, fields and data in mind look at the following three queries: > SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-02-01'; > SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-01-20'; > SELECT COUNT(distinct model) FROM inventory WHERE modified >= '2010-01-01'; > All three of the above queries work and provide results. However, I want to combine the three into one SQL Statement thathits the database one time. How can I do this in one SQL Statement? Is it possible with sub select? > Here is what result I am looking for from one SELECT statement using the data example from above: > count1 | count2 | count3 > ------------------------------- > 2 2 4 > Can this be done with ONE SQL STATEMENT? touching the database only ONE time? > Please let me know. > Thanx> :) > NEiL > Здесь спама нет http://mail.yandex.ru/nospam/sign
В списке pgsql-sql по дате отправления: