help with SQL join
Hello,
I need help with the an advanced SQL JOIN. I think that I can get this accomplished with a LEFT JOIN... perhaps some of you may be able to offer guidance in this... I appreciate any suggestions you may have.
Consider the following SQL statement:
SELECT customerid, count(disctint count1) AS "TODAYS_USERS",
count(distinct count2) AS "LAST 7 DAYS" ,
count(distinct count3) AS "LAST 30 DAYS" FROM
(SELECT distinct case when modified >= '2010-02-11' then modelnumber else null end as count1,
case when modified >= '2010-02-04' then modelnumber else null end as count2,
case when modified >= '2010-01-11' then modelnumber else null end as count3, customerid
FROM sales WHERE modelnumber LIKE 'GH77%')
AS results GROUP BY results.customerid
Now, the above SQL query retrieves results that will look something like this:
customerid | TODAYS_USERS | LAST 7 DAYS | LAST 30 DAYS
bigint | bigint | bigint | bigint
----------------------------------------------------------------------
8699 | 1 | 1 | 1
8700 | 1 | 12 | 17
8701 | 3 | 5 | 19
Now... here is the problem I am having... the above SQL query is retrieving results from one table: sales
I have another table called customers with a couple of fields (customerid, and customername are two of the fields).
I want to join on the customerid in both tables to retrieve the customername in the query.
So I need the results to look something like this:
customerid | customername | TODAYS_USERS | LAST 7 DAYS | LAST 30 DAYS
bigint | varchar | bigint | bigint | bigint
--------------------------------------------------------------------------------------------------------------------------------
8699 | Joe Smith | 1 | 1 | 1
8700 | Sara Olson | 1 | 12 | 17
8701 | Mike Jones | 3 | 5 | 19
Can someone show me how to use a JOIN with the above SQL Statement? I need to bring the customername field into the query from the other table and I have been having issues writting the query... can this even be done?
Thanks,
Neil
Neil Stlyz wrote:
Now... here is the problem I am having... the above SQL query is
retrieving results from one table: sales
I have another table called customers with a couple of fields
(customerid, and customername are two of the fields).
I want to join on the customerid in both tables to retrieve the
customername in the query.
So I need the results to look something like this:customerid | customername |
TODAYS_USERS | LAST 7 DAYS | LAST 30 DAYS
bigint | varchar |
bigint | bigint
| bigint
--------------------------------------------------------------------------------------------------------------------------------
8699 | Joe Smith | 1
|
1 | 1
8700 | Sara Olson | 1
| 12
| 17
8701 | Mike Jones | 3
|
5 | 19Can someone show me how to use a JOIN with the above SQL Statement? I
need to bring the customername field into the query from the other
table and I have been having issues writting the query... can this
even be done?
something like...
SELECT results.customerid, c.customername, count(distinct count1) AS
"TODAYS_USERS",
count(distinct count2) AS "LAST 7 DAYS" ,
count(distinct count3) AS "LAST 30 DAYS"
FROM (SELECT distinct case when s.modified >= '2010-02-11' then
s.modelnumber else null end as count1,
case when s.modified >= '2010-02-04' then s.modelnumber else null
end as count2,
case when s.modified >= '2010-01-11' then s.modelnumber else null
end as count3, s.customerid
FROM sales as s WHERE s.modelnumber LIKE 'GH77%') AS results
JOIN customers as c ON (results.customerid = c.customerid)
GROUP BY results.customerid
-----Original Message-----
From: John R Pierce [mailto:pierce@hogranch.com]
Sent: Thursday, February 11, 2010 3:01 PM
To: pgsql-general@postgresql.org
Subject: Re: help with SQL joinNeil Stlyz wrote:
Now... here is the problem I am having... the above SQL query is
retrieving results from one table: sales I have anothertable called
customers with a couple of fields (customerid, and customername are
two of the fields).
I want to join on the customerid in both tables to retrieve the
customername in the query.
So I need the results to look something like this:customerid | customername |
TODAYS_USERS | LAST 7 DAYS |LAST 30 DAYS
bigint | varchar |
bigint | bigint| bigint
--------------------------------------------------------------
------------------------------------------------------------------8699 | Joe Smith |
1
|
1 | 1
8700 | Sara Olson |1
| 12
| 17
8701 | Mike Jones |3
|
5 | 19Can someone show me how to use a JOIN with the above SQL
Statement? I
need to bring the customername field into the query from the other
table and I have been having issues writting the query... can this
even be done?something like...
SELECT results.customerid, c.customername, count(distinct
count1) AS "TODAYS_USERS", count(distinct count2) AS "LAST 7
DAYS" , count(distinct count3) AS "LAST 30 DAYS"
FROM (SELECT distinct case when s.modified >=
'2010-02-11' then s.modelnumber else null end as count1,
case when s.modified >= '2010-02-04' then
s.modelnumber else null end as count2,
case when s.modified >= '2010-01-11' then
s.modelnumber else null end as count3, s.customerid
FROM sales as s WHERE s.modelnumber LIKE 'GH77%')
AS results
JOIN customers as c ON (results.customerid = c.customerid)
GROUP BY results.customerid
One correction: you should "group" on all non-aggregate columns in your
"select" list, i.e.:
SELECT results.customerid, c.customername, count(distinct
count1) AS "TODAYS_USERS", count(distinct count2) AS "LAST 7
DAYS" , count(distinct count3) AS "LAST 30 DAYS"
FROM (SELECT distinct case when s.modified >=
'2010-02-11' then s.modelnumber else null end as count1,
case when s.modified >= '2010-02-04' then
s.modelnumber else null end as count2,
case when s.modified >= '2010-01-11' then
s.modelnumber else null end as count3, s.customerid
FROM sales as s WHERE s.modelnumber LIKE 'GH77%')
AS results
JOIN customers as c ON (results.customerid = c.customerid)
GROUP BY results.customerid, c.customername
Igor Neyman