SQL JOIN 3 TABLES WITH COUNT AND GROUP BY CLAUSE - sql

I Have 3 tables like that:
EXPEDITION (ID, CreateDate, Status);
PACKAGE (ID, EXPEDITION_ID)
ITEM (ID, EXPEDIITONPACKAGE_ID);
I need to know, for each expedition, the quantity of packages and the quantity of items.

UPDATE
This is the query that seems to have it.
SELECT
E.ID,
P.Packages,
I.Items
FROM EXPEDITION E
LEFT JOIN (
SELECT DISTINCT E.ID, COUNT(P.ID) AS "Packages" FROM EXPEDITION E
LEFT JOIN PACKAGE P
ON E.ID = P.EXPEDITION_ID
GROUP BY E.ID
) P
ON E.ID = P.ID
LEFT JOIN (
SELECT DISTINCT P.ID as "PackageID", COUNT(I.ID) AS "Items" FROM PACKAGE P
JOIN ITEM I
ON P.ID = I.EXPEDIITONPACKAGE_ID
GROUP BY P.ID
) I
ON P.ID = I.PackageId
GROUP BY
E.ID,
P.Packages,
I.Items
ORDER BY
E.ID
It has two inner queries, that count the IDs separately, and they are joined in the main query to show the results.

Try this. Not tested yet...but it should work..
;With c1 as
(
Select e.expid, count(e.expid) as qtyPck
From packages p inner join
Expeditions e on p.expid = e.expid
Group by e.expid
),
C2 as
(
Select i.pakId, count(i.pakId) as qtyItems
From items i inner join packages p
On i.pakId = p.pakId
Group by i.pakid
)
Select e.expId, p.qtyPck, I.qtyItems
From expeditions e
Join packages p on p.expId = e.expId
Join items i on i.pakId = p.pakId;

Related

Re-writing query from in() to joins

Can you assist in re-writing this into joins?
select * from users where users.advised_by in (
select p.id
from advisors p
join advisor_members m on p.id = m.advisor_id
join representatives r on m.user_id=r.user_id
where m.memeber_type='Advisor'
)
This is part of 200+ row query and that in() statement is hard to maintain when there are changes.
you should use a proper on clause
select *
from users
inner join
(
select p.id
from advisors p
join advisor_members m on p.id = m.advisor_id
join representatives r on m.user_id=r.user_id
where m.memeber_type='Advisor'
) t on users.advised_by = t.id
/*Option 1 */
SELECT *
FROM users usr
INNER JOIN
(
SELECT p.id AS advisor_id
FROM advisors p
JOIN advisor_members m
ON p.id = m.advisor_id
JOIN representatives r
ON m.user_id=r.user_id
WHERE m.memeber_type='Advisor' ) T2 usr.advised_by = t2.advisor_id
/*Option2 -- */
SELECT *
FROM users usr
INNER JOIN advisors p
ON usr.advised_by=p.id
JOIN
(
SELECT *
FROM advisor_members
WHERE m.memeber_type='Advisor') m
ON p.id = m.advisor_id
JOIN representatives r
ON m.user_id=r.user_id

How to make LEFT JOIN with row having max date?

I have two tables in Oracle DB
Person (
id
)
Bill (
id,
date,
amount,
person_id
)
I need to get person and amount from last bill if exist.
I trying to do it this way
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN Bill b
ON b.person_id = p.id AND b.date = (SELECT MAX(date) FROM Bill WHERE person_id = 1)
WHERE p.id = 1;
But this query works only with INNER JOIN. In case of LEFT JOIN it throws ORA-01799 a column may not be outer-joined to a subquery
How can I get amoun from the last bill using left join?
Please try the below avoiding sub query to be outer joined
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN(select * from Bill where date =
(SELECT MAX(date) FROM Bill b1 WHERE person_id = 1)) b ON b.person_id = p.id
WHERE p.id = 1;
What you are looking for is a way to tell in bills, for each person, what is the latest record, and that one is the one to join with. One way is to use row_number:
select * from person p
left join (select b.*,
row_number() over (partition by person_id order by date desc) as seq_num
from bills b) b
on p.id = b.person_id
and seq_num = 1
You cannot have a subquery inside an ON statement.
Instead you need to convert your LEFT JOIN statement into a whole subquery.
Not tested but this should work.
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN (
SELECT id FROM Bill
WHERE person_id = p.id
AND date = (SELECT date FROM Bill WHERE person_id = 1)) b
WHERE p.id = 1;
I'm not quite sure why you would want to filter for the date though.
Simply filtering for the person_id should do the trick
you should join Person and Bill to the result for max date in bill related to person_id
select Person.id, bill.amount
from Person
left join bill on bill.person_id = person.id
left join (
select person_id, max(date) as max_date
from bill
group by person_id ) t on t.person_id = Person.id and b.date = t.max_date
Hey you can do like this
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN Bill b
ON b.person_id = p.id AND b.date = (SELECT max(date) FROM Bill WHERE person_id = 1)
WHERE p.id = 1
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN Bill b
ON b.person_id = p.id
WHERE (SELECT max(date) FROM bill AS sb WHERE sb.person_id=p.id LIMIT 1)=b.date;
SELECT
p.id,
c.amount
FROM Person p
LEFT JOIN (select b.person_id as personid,b.amount as amount from Bill b where b.date1= (select max(date1) from Bill where person_id=1)) c
ON c.personid = p.id
WHERE p.id = 1;
try this
select * from person p
left join (select MAX(id) KEEP (DENSE_RANK FIRST ORDER BY date DESC)
from bills b) b
on p.id = b.person_id
I use GREATEST() function in join condition:
SELECT
p.id,
b.amount
FROM Person p
LEFT JOIN Bill b
ON b.person_id = p.id
AND b.date = GREATEST(b.date)
WHERE p.id = 1
This allows you to grab the whole row if necessary and grab the top x rows
SELECT p.id
,b.amount
FROM person p
LEFT JOIN
(
SELECT * FROM
(
SELECT date
,ROW_NUMBER() OVER (PARTITION BY person_id ORDER BY date DESC) AS row_num
FROM bill
)
WHERE row_num = 1
) b ON p.id = b.person_id
WHERE p.id = 1
;

SQL Server Circular Query

I have 4 tables, in that I want to fetch records from all 4 and aggregate the values
I have these tables
I am expecting this output
but getting this output as a Cartesian product
It is multiplying the expenses and allocation
Here is my query
select
a.NAME, b.P_NAME,
sum(a.DURATION) DURATION,
sum(b.[EXP]) EXPEN
from
(select
e.ID, a.P_ID, e.NAME, a.DURATION DURATION
from
EMPLOYEE e
inner join
ALLOCATION a ON e.ID = a.E_ID) a
inner join
(select
p.P_ID, e.E_ID, p.P_NAME, e.amt [EXP]
from
PROJECT p
inner join
EXPENSES e ON p.P_ID = e.P_ID) b ON a.ID = b.E_ID
and a.P_ID = b.P_ID
group by
a.NAME, b.P_NAME
Can anyone suggest something about this.
The following should work:
SELECT e.Name,p.Name,COALESCE(d.Duration,0),COALESCE(exp.Expen,0)
FROM
Employee e
CROSS JOIN
Project p
LEFT JOIN
(SELECT E_ID,P_ID,SUM(Duration) as Duration FROM Allocation
GROUP BY E_ID,P_ID) d
ON
e.E_ID = d.E_ID and
p.P_ID = d.P_ID
LEFT JOIN
(SELECT E_ID,P_ID,SUM(AMT) as Expen FROM Expenses
GROUP BY E_ID,P_ID) exp
ON
e.E_ID = exp.E_ID and
p.P_ID = exp.P_ID
WHERE
d.E_ID is not null or
exp.E_ID is not null
I've tried to write a query that will produce results where e.g. there are rows in Expenses but no rows in Allocations (or vice versa) for some particular E_ID,P_ID combination.
Use left join in select query by passing common id for all table
Hi I got the answer what I want from some modification in the query
The above query is also working like a charm and have done some modification to the original query and got the answer
Just have to group by the inner queries and then join the queries it will then not showing Cartesian product
Here is the updated one
select a.NAME,b.P_NAME,sum(a.DURATION) DURATION,sum(b.[EXP]) EXPEN from
(select e.ID,a.P_ID, e.NAME,sum(a.DURATION) DURATION from EMPLOYEE e inner join ALLOCATION a
ON e.ID=a.E_ID group by e.ID,e.NAME,a.P_ID) a
inner join
(select p.P_ID,e.E_ID, p.P_NAME,sum(e.amt) [EXP] from PROJECT p inner join EXPENSES e
ON p.P_ID=e.P_ID group by p.P_ID,p.P_NAME,e.E_ID) b
ON a.ID=b.e_ID and a.P_ID=b.P_ID group by a.NAME,b.P_NAME
Showing the correct output

SQL: Have 4 Tables, Looking to find unmatched data

I've always done this back asswards in PHP or ASAP, so I figure it's time to actually learn the proper way to do it in SQL. I have the following 4 tables in a database:
Category (Fields: CategoryNumber, Desc) (small table with 15 rows)
Media (Fields: MediaID, Desc, CategoryNumber, etc) (huge table with 15,000 rows)
Sales (Fields: Date, MediaID, EmployeeID etc) (huge table with 100,000 rows)
Employees (Fields: EmployeeID, Name, etc) (small table with only 20 rows)
Category only links to Media
Media has links to both Category and Sales.
Sales links to both the Media and Employee
Employee only links to Sales
What I would like to do is to write a query which tells me what categories a given employee has never sold any media in.
I can write a simple query that looks for unmatched data between 2 tables, but I have no clue how to do it when I'm dealing with 4 tables.
Thanks for your time and help!
Here's my suggestion:
select *
from Category c
where not exists (
select *
from Employee e
inner join Sales s on s.EmployeeId = e.EmployeeId
inner join Media m on m.MediaID = s.MediaID
where e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber
)
To query all employes with the categories in which they didn't sell anything:
select e.EmployeeName, c.CategoryNumber
from Category c
cross join Employee e
where not exists (
select *
from Sales s
inner join Media m on m.MediaID = s.MediaID
where c.categoryNumber = m.CategoryNumber
and s.EmployeeId = e.EmployeeId
)
SELECT c.CategoryNumber, c.Desc
FROM Category c
WHERE NOT EXISTS
(
SELECT *
FROM Employees e
INNER JOIN Sales s on s.EmployeeID = e.EmployeeID
INNER JOIN Media m on m.MediaID = s.MediaID
WHERE e.Name = "Ryan"
AND m.CategoryNumber = c.CategoryNumber
)
MS Access evidently needs a lot of parentheses (thanks, Ryan!):
select *
from Category c
where not exists
( select *
from ( Employee e
inner join Sales s on (s.EmployeeId = e.EmployeeId))
inner join Media m on (m.MediaID = s.MediaID)
where (e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber) )
select c.desc
from category
left outer join (select s.employeeid,m.categorynumber
from sales s
inner join media m on s.mediaid=m.mediaid
inner join employee e on e.employeeid=s.employeeid
where e.name = 'JOE'
group by employeeid,categorynumber) t on t.categorynumber=c.categorynumber
where s.employeeid is null
Modified Answer based on the solution provided by Carl in Access SQL Syntax:
select *
from Category c
where not exists (
select *
from (Employee e
inner join Sales s on (s.EmployeeId = e.EmployeeId))
inner join Media m on (m.MediaID = s.MediaID)
where (e.Name = 'Ryan' and m.CategoryNumber = c.CategoryNumber)
)

Why are my SQL statement count different fields from differrent tables in one SQL statement?

I have a SQL query:
SELECT
e.name as estate_name
, g.name as governing_body
, count(s.id) as total_stands
, count(sp.id) as service_providers
FROM estates e
LEFT JOIN governing_bodies
ON e.governing_body_id = g.id
LEFT JOIN stands s
ON s.estate_id = e.id
LEFT JOIN services sp
ON sp.estate_id = e.id
GROUP BY e.id
It seems like my counts multiply each other. If my first count is 3 and second count is 10 the results in service_providers field and total_stands field will be 30.
What am I doing wrong?
What about changing the COUNT(blah) constructs to COUNT(DISTINCT blah) ?
A count() displays the number of rows found for your group. Since you're grouping on estate, it will count the number of rows you join to estate. Joins will multiply the number of rows, so 3 x 10 = 30 sounds like the correct count. Run the query without GROUP BY to see what's happening.
One way to fix it would look like this:
SELECT
e.name as estate_name,
g.name as governing_body,
(select count(*) from stands s where s.estate_id = e.id) as stands,
(select count(*) from services sp where sp.estate_id = e.id) as services
FROM estates e
LEFT JOIN governing_bodies g on e.governing_body_id = g.id
Writing out Alex Martelli's informative answer:
SELECT
e.name as estate_name
, g.name as governing_body
, count(distinct s.id) as total_stands
, count(distinct sp.id) as service_providers
FROM estates e
LEFT JOIN governing_bodies
ON e.governing_body_id = g.id
LEFT JOIN stands s
ON s.estate_id = e.id
LEFT JOIN services sp
ON sp.estate_id = e.id
GROUP BY e.id, g.name
Or, as a more complex alternative with JOIN syntax:
SELECT
e.name as estate_name,
g.name as governing_body,
IsNull(stand_count.total,0) as stand_count,
IsNull(service_count.total,0) as service_count
FROM estates e
LEFT JOIN governing_bodies g on e.governing_body_id = g.id
LEFT JOIN (
select estate_id, total = count(*) from stands group by estate_id
) stand_count on stand_count.estate_id = e.id
LEFT JOIN (
select estate_id, total = count(*) from services group by estate_id
) service_count on service_count.estate_id = e.id
GROUP BY
e.name,
g.name,
IsNull(stand_count.total,0),
IsNull(service_count.total,0)