PostgreSQL select multiple columns of a table that is connected via a many-to-many pivot - sql

I have this query:
SELECT
a.account_uuid,
a.account_no,
a.account_group_uuid,
a.account_scope_uuid,
a.created_at,
a.deleted_at,
s.service_uuid,
s.status,
st.service_type,
(
SELECT
c.company
FROM companies c
WHERE a.company_owner_uuid = c.company_uuid
)
FROM
accounts a
LEFT JOIN
services s
ON a.account_uuid = s.account_uuid
LEFT JOIN
service_types st
ON s.service_type_uuid = st.service_type_uuid
WHERE
a.deleted_at IS NULL
ORDER BY
a.account_no
And I need to join and select multiple columns from a people table by way of a pivot table accounts_contacts that would have the account_uuid and a person_uuid. There are also is_primary and is_active columns on the accounts_contacts table and there will only be one primary at a time, so the end result would be a single first and last name. This is the idea of the query:
SELECT
p.first_name, p.last_name
FROM
people p
INNER JOIN
accounts_contacts ac
ON ac.account_uuid = a.account_uuid
AND ac.person_uuid = p.person_uuid
WHERE
ac.is_primary = true
AND ac.is_active = true
But not sure how to fit it into the above query. A subquery would only allow for one of the columns.

account_contacts is an "association" or "junction" table. It is not a pivot table.
The basic idea should be joins:
SELECT . . . ,
p.first_name, p.last_name
FROM accounts a LEFT JOIN
services s
ON a.account_uuid = s.account_uuid LEFT JOIN
service_types st
ON s.service_type_uuid = st.service_type_uuid LEFT JOIN
accounts_contacts ac
ON ac.account_uuid = a.account_uuid LEFT JOIN
people p
ON ac.person_uuid = p.person_uuid AND
ac.is_primary = true AND
ac.is_active = true

Related

How to create distinct count from queries with several tables

I am trying to create one single query that will give me a distinct count for both the ActivityID and the CommentID. My query in MS Access looks like this:
SELECT
tbl_Category.Category, Count(tbl_Activity.ActivityID) AS CountOfActivityID,
Count(tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;
I know the answer must somehow include SELECT DISTINCT but am not able to get it to work. Do I need to create multiple subqueries?
This is really painful in MS Access. I think the following does what you want to do:
SELECT ac.Category, ac.num_activities, aco.num_comments
FROM (SELECT ca.category, COUNT(*) as num_activities
FROM (SELECT DISTINCT c.Category, a.ActivityID
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as caa
GROUP BY ca.category
) as ca LEFT JOIN
(SELECT c.Category, COUNT(*) as num_comments
FROM (SELECT DISTINCT c.Category, co.CommentId
FROM (tbl_Category as c INNER JOIN
tbl_Activity as a
ON c.CategoryID = a.CategoryID
) INNER JOIN
tbl_Comments as co
ON a.ActivityID = co.ActivityID
WHERE a.UnitID = 5 AND co.PeriodID = 1
) as aco
GROUP BY c.Category
) as aco
ON aco.CommentId = ac.CommentId
Note that your LEFT JOINs are superfluous because the WHERE clause turns them into INNER JOINs. This adjusts the logic for that purpose. The filtering is also very tricky, because it uses both tables, requiring that both subqueries have both JOINs.
You can use DISTINCT:
SELECT
tbl_Category.Category, Count(DISTINCT tbl_Activity.ActivityID) AS CountOfActivityID,
Count(DISTINCT tbl_Comments.CommentID) AS CountOfCommentID
FROM tbl_Category LEFT JOIN
(tbl_Activity LEFT JOIN tbl_Comments ON
tbl_Activity.ActivityID = tbl_Comments.ActivityID) ON
tbl_Category.CategoryID = tbl_Activity.CategoryID
WHERE
(((tbl_Activity.UnitID)=5) AND ((tbl_Comments.PeriodID)=1))
GROUP BY
tbl_Category.Category;

Get all data for an entity from another table in one query

I have this query
select *
from (
select c.*,p.name as project_name,u.firstname || ' ' || u.lastname as fullname, u.email as owner_email, u.payment_method, u as user, u.id as user_id, u.api_id, u.api_key,
v.name as vendor_name, v.exid as vendor_id, s.number as sim_number, vm.exid as vendor_model_id, vm.name as vendor_model_name, cr.status as is_recording,
cr.storage_duration as cloud_recording_storage_duration, cr.schedule as schedule, cr.frequency as frequency,
(select count(id) as total from camera_shares cs where c.id=cs.camera_id) as total_share
from cameras c
inner JOIN users u on c.owner_id = u.id
left JOIN projects p on c.project_id = p.id
left JOIN sims s on c.id = s.camera_id
left JOIN vendor_models vm on c.model_id = vm.id
left JOIN vendors v on vm.vendor_id = v.id
left JOIN cloud_recordings cr on c.id = cr.camera_id
) c
this gives me all cameras and with all relevant values which I require.
now there is another table, snapshot_extractors and it has a relation with the camera on id and camera_id in extractors table, as one camera can have more than 1 extractors.
In the above query, I want to get all extraction for one camera, I can do it in a separate query, but is it possible to get all extractions in the above query as an array of all extractions for a camera?
You can use another correlated subquery:
(select array_agg(e.extraction)
from snapshot_extractors e
where e.camera_id = c.camera_id
)

Access Subquery On mulitple conditions

This SQL query needs to be done in ACCESS.
I am trying to do a subquery on the total sales, but I want to link the sale to the province AND to product. The below query will work with one or the other: (po.product_name = allp.all_products) AND (p.province = allp.all_province); -- but it will no take both.
I will be including every month into this query, once I can figure out the subquery on with two criteria.
Select
p.province as [Province],
po.product_name as [Product],
all_price
FROM
(purchase_order po
INNER JOIN person p
on p.person_id = po.person_id)
left join
(
select
po1.product_name AS [all_products],
sum(pp1.price) AS [all_price],
p1.province AS [all_province]
from (purchase_order po1
INNER JOIN product pp1
on po1.product_name = pp1.product_name)
INNER JOIN person p1
on po1.person_id = p1.person_id
group by po1.product_name, pp1.price, p1.province
)
as allp
on (po.product_name = allp.all_products) AND (p.province = allp.all_province);
Make the first select sql into a table by giving it an alias and join table 1 to table 2. I don't have your table structure or data to test it but I think this will lead you down the right path:
select table1.*, table2.*
from
(Select
p.province as [Province],
po.product_name as [Product]
--removed this ,all_price
FROM
(purchase_order po
INNER JOIN person p
on p.person_id = po.person_id) table1
left join
(
select
po1.product_name AS [all_products],
sum(pp1.price) AS [all_price],
p1.province AS [all_province]
from (purchase_order po1
INNER JOIN product pp1
on po1.product_name = pp1.product_name)
INNER JOIN person p1
on po1.person_id = p1.person_id
group by po1.product_name, pp1.price, p1.province --check your group by, I dont think you want pp1.price here if you want to aggregate
) as table2 --changed from allp
on (table1.product = table2.all_products) AND (table1.province = table2.all_province);

Join on TOP 1 from subquery while referencing outer tables

I am starting with this query, which works fine:
SELECT
C.ContactSys
, ... a bunch of other rows...
FROM Users U
INNER JOIN Contacts C ON U.ContactSys = C.ContactSys
LEFT JOIN UserWatchList UW ON U.UserSys = UW.UserSys
LEFT JOIN Accounts A ON C.AccountSys = A.AccountSys
WHERE
C.OrganizationSys = 1012
AND U.UserTypeSys = 2
AND C.FirstName = 'steve'
Now, I've been given this requirement:
For every visitor returned by the Visitor Search, take ContactSys, get the most recent entry in the GuestLog table for that contact, then return the columns ABC and XYZ from the GuestLog table.
I'm having trouble with that. I need something like this (I think)...
SELECT
C.ContactSys
, GL.ABC
, GL.XYZ
, ... a bunch of other rows...
FROM Users U
INNER JOIN Contacts C ON U.ContactSys = C.ContactSys
LEFT JOIN UserWatchList UW ON U.UserSys = UW.UserSys
LEFT JOIN Accounts A ON C.AccountSys = A.AccountSys
LEFT JOIN (SELECT TOP 1 * FROM GuestLog GU WHERE GU.ContactSys = ????? ORDER BY GuestLogSys DESC) GL ON GL.ContactSys = C.ContactSys
WHERE
C.OrganizationSys = 1012
AND U.UserTypeSys = 2
AND C.FirstName = 'steve'
Only that's not it because that subquery on the JOIN doesn't know anything about the outer tables.
I've been looking at these posts and their answers, but I'm having a hard time translating them to my needs:
SQL: Turn a subquery into a join: How to refer to outside table in nested join where clause?
Reference to outer query in subquery JOIN
Referencing outer query in subquery
Referencing outer query's tables in a subquery
If that is the logic you want, you can use OUTER APPLY:
SELECT C.ContactSys, GL.ABC, GL.XYZ,
... a bunch of other columns ...
FROM Users U JOIN
Contacts C
ON U.ContactSys = C.ContactSys LEFT JOIN
UserWatchList UW
ON U.UserSys = UW.UserSys LEFT JOIN
Accounts A
ON C.AccountSys = A.AccountSys OUTER APPLY
(SELECT TOP 1 gl.*
FROM GuestLog gl
WHERE gl.ContactSys = C.ContactSys
ORDER BY gl.GuestLogSys DESC
) GL
WHERE C.OrganizationSys = 1012 AND
U.UserTypeSys = 2 AND
C.FirstName = 'steve'

sql subquery join group by

I am trying to get a list of our users from our database along with the number of people from the same cohort as them - which in this case is defined as being from the same medical school at the same time.
medical_school_id is stored in the doctor_record table
graduation_dt is stored in the doctor_record table as well.
I have managed to write this query out using a subquery which does a select statement counting the number of others for each row but this takes forever. My logic is telling me that I ought to run a simple GROUP BY query once first and then somehow JOIN the medical_school_id on to that.
The group by query is as follows
select count(ca.id) , cdr.medical_school_id, cdr.graduation_dt
from account ca
LEFT JOIN doctor cd on ca.id = cd.account_id
LEFT JOIN doctor_record cdr on cd.gmc_number = cdr.gmc_number
GROUP BY cdr.medical_school_id, cdr.graduation_dt
The long select query is
select a.id, a.email , dr.medical_school_id,
(select count(ba.id) from account ba
LEFT JOIN doctor bd on ba.id = bd.account_id
LEFT JOIN doctor_record bdr on bd.gmc_number = bdr.gmc_number
WHERE bdr.medical_school_id = dr.medical_school_id AND bdr.graduation_dt = dr.graduation_dt) AS med_count,
from account a
LEFT JOIN doctor d on a.id = d.account_id
LEFT JOIN doctor_record dr on d.gmc_number = dr.gmc_number
If you could push me in the right direction that would be amazing
I think you just want window functions:
select a.id, a.email, dr.medical_school_id, dr.graduation_dt,
count(*) over (partition by dr.medical_school_id, dr.graduation_dt) as cohort_size
from account a left join
doctor d
on a.id = d.account_id left join
doctor_record dr
on d.gmc_number = dr.gmc_number;
Using your same code for group by:
SELECT * FROM (
(
SELECT acc.[id]
, acc.[email]
FROM
account acc
LEFT JOIN
doctor doc
ON
acc.id = doc.account_id
LEFT JOIN
doctor_record doc_rec
ON
doc.gmc_number = doc_rec.gmc_number
) label
LEFT JOIN
(
SELECT count(acco.id)
, doc_reco.medical_school_id
, doc_reco.graduation_dt
FROM
account acco
LEFT JOIN
doctor doct
ON
acco.id = doct.account_id
LEFT JOIN
doctor_record doc_reco
ON
doct.gmc_number = doc_reco.gmc_number
GROUP BY
doc_reco.medical_school_id,
doc_reco.graduation_dt
) count
ON
count.[medical_school_id]=label.[medical_school_id]
AND
count.[graduation_dt]=label.[graduation_date]
)
how about something like this?
select a.doctor_id
, count(*) - 1
from doctor_record a
left join doctor_record b on a.medical_school_id = b.medical_school_id
and a.graduation_dt = b.graduation_dt
group by a.doctor_id
Subtract 1 from the count so that you're not counting the doctor in the "other folks in same cohort" number
I'm defining "same cohort" as "same medical school & graduation date".
I'm unclear on what GMC number is and how it is related. Is it something to do with cohort?