I am trying to write a query that connects 3 tables.
The first table is info about each festival.
The second table is the number of votes for each festival.
The third table is reviews for each festival.
I want to join all 3 tables so I get all the columns from table1, join table1 with table2 on the festivalid, but I also need to count the number of records in table 3 that apply to each festival.
The first 2 tables give me a result because they both have data in them but table 3 is empty because there are no reviews yet so adding that to my query gives me no results.
SELECT f.*,
v.total,
v.votes,
v.festivalid,
r.reviewcount as count
FROM festivals f
INNER
JOIN vote v
ON f.festivalid = v.festivalid
INNER
JOIN (SELECT festivalid,
count(*) as reviewcount
FROM reviews)
GROUP BY festivalid) as r
on r.festivalid = v.festivalid
LEFT OUTER JOIN
e.g.
SELECT f.*,
v.total,
v.votes,
v.festivalid,
r.reviewcount as count
FROM festivals f
INNER
JOIN vote v
ON f.festivalid = v.festivalid
LEFT OUTER
JOIN (SELECT festivalid,
count(*) as reviewcount
FROM reviews
GROUP BY festivalid) as r
on r.festivalid = v.festivalid
SELECT f.*,
v.total,
v.votes,
v.festivalid,
ifnull(r.reviewcount,0) as count
FROM festivals f
INNER
JOIN vote v
ON f.festivalid = v.festivalid
LEFT OUTER
JOIN (SELECT festivalid,
count(*) as reviewcount
FROM reviews)
GROUP BY festivalid) as r
on r.festivalid = v.festivalid
added ifnull to show reviews as 0 in case there are none.
The second join shouldn't be an inner join.
SELECT f.*,
v.total,
v.votes,
v.festivalid,
r.reviewcount as count
FROM festivals f
INNER
JOIN vote v
ON f.festivalid = v.festivalid
LEFT OUTER
JOIN (SELECT festivalid,
count(*) as reviewcount
FROM reviews
GROUP BY festivalid) as r
on r.festivalid = v.festivalid
Article on outer joins:
http://msdn.microsoft.com/en-us/library/ms187518.aspx
Try using a outer join on your review count table (r)
SELECT f.*,
v.total,
v.votes,
v.festivalid,
r.reviewcount as count
FROM festivals f
INNER
JOIN vote v
ON f.festivalid = v.festivalid
LEFT OUTER
JOIN (SELECT festivalid,
count(*) as reviewcount
FROM reviews)
GROUP BY festivalid) as r
on r.festivalid = v.festivalid
Related
I have three tables, and I join them and use where Group by - count, I could not get the countries with zero results in the output. I am still lost.
Here is the SQLfiddle
http://sqlfiddle.com/#!4/e330ec/7
CURRENT OUTPUT
(UKD) 3
(EUR) 2
(USA) 2
(CHE) 1
EXPECTED OUTPUT
(UKD) 3
(EUR) 2
(IND) 0
(LAO) 0
(USA) 2
(CHE) 1
You can use a RIGHT JOIN as suggested in another answer or you can reorder your joins and use a LEFT JOIN:
SELECT
C.COUNTRY_CODE,
COUNT(GAME_TYPE)
FROM
COUNTRY_TABLE C
LEFT JOIN PLAYER_TABLE P ON P.COUNTRY_ID = C.COUNTRY_ID
LEFT JOIN PLAYER_GAME_TYPE G ON P.PLAYER_ID = G.PLAYER_ID
WHERE
G.GAME_TYPE = 'GOLF'
OR G.GAME_TYPE IS NULL
GROUP BY
C.COUNTRY_CODE;
Note the inclusion of OR G.GAME_TYPE IS NULL in the WHERE clause -- if you only have G.GAME_TYPE = 'GOLF', then desired results will be filtered out after the joins.
You can prefer applying the following steps as an option :
convert second LEFT JOIN to RIGHT JOIN(since desired missing abbreviations are in COUNTRY_TABLE which stays at right)
make the filtering condition(followed by the WHERE clause) G.GAME_TYPE = 'GOLF' a match condition
by taking next to the ON clause
such as
SELECT C.COUNTRY_CODE, COUNT(GAME_TYPE)
FROM PLAYER_TABLE P
LEFT JOIN PLAYER_GAME_TYPE G
ON P.PLAYER_ID = G.PLAYER_ID
RIGHT JOIN COUNTRY_TABLE C
ON P.COUNTRY_ID = C.COUNTRY_ID
AND G.GAME_TYPE = 'GOLF'
GROUP BY C.COUNTRY_CODE;
Demo
The simple change of tables join order can solve the problem
SELECT C.COUNTRY_CODE, COUNT(GAME_TYPE)
FROM COUNTRY_TABLE C -- get all countries
LEFT JOIN PLAYER_TABLE P ON P.COUNTRY_ID = C.COUNTRY_ID -- join all players
LEFT JOIN PLAYER_GAME_TYPE G ON P.PLAYER_ID = G.PLAYER_ID AND G.GAME_TYPE = 'GOLF' -- join only GOLF games
GROUP BY C.COUNTRY_CODE;
sqlize online
This is your query:
SELECT C.COUNTRY_CODE, COUNT(GAME_TYPE)
FROM PLAYER_TABLE P
LEFT JOIN PLAYER_GAME_TYPE G ON P.PLAYER_ID = G.PLAYER_ID
LEFT JOIN COUNTRY_TABLE C ON P.COUNTRY_ID = C.COUNTRY_ID
WHERE G.GAME_TYPE = 'GOLF'
GROUP BY C.COUNTRY_CODE;
This query seems to try to select all players even when they are no golfers. This doesn't work, however, as WHERE G.GAME_TYPE = 'GOLF' removes all outer joined rows, so you end up with an inner join (all players who play golf.) At last you outer join the countries table, which would give you players that don't belong to a country. Is this indented? I don't think so.
What you want is countries, so select from countries. Then properly outer join players and types in order to count them.
SELECT c.country_code, COUNT(g.game_type) as golfers_in_country
FROM country_table c
LEFT JOIN player_table p ON p.country_id = c.country_id
LEFT JOIN player_game_type g ON g.player_id = p.player_id AND g.game_type = 'GOLF'
GROUP BY c.country_code
ORDER BY c.country_code;
You can use a CTE to get this more readable. It is longer, but makes the intention crystal-clear. Structuring one's queries like this helps avoiding mistakes.
WITH golfers AS
(
SELECT *
FROM player_table
WHERE player_id IN
(
SELECT player_id
FROM player_game_type
WHERE game_type = 'GOLF'
)
)
SELECT c.country_code, COUNT(g.player_id) as golfers_in_country
FROM country_table c
LEFT JOIN golfers g ON g.country_id = c.country_id
GROUP BY c.country_code
ORDER BY c.country_code;
My SQL query looks like this
SELECT *
FROM categories AS c
LEFT JOIN LATERAL (SELECT i.*
FROM influencer_profiles AS i
WHERE c.id = i.category_id
ORDER BY i.updated_at
LIMIT 2) AS i ON 1 = 1
INNER JOIN users AS u ON i.user_id = u.id
But I also want to count each influencer_profile for category to display how many influencer_profiles in each categories. How can I use COUNT(*) with selecting all columns?
SELECT *
FROM categories AS c
LEFT JOIN LATERAL (SELECT COUNT(*)
FROM influencer_profiles AS i
WHERE c.id = i.category_id
ORDER BY i.updated_at
LIMIT 2) AS i ON 1 = 1
INNER JOIN users AS u ON i.user_id = u.id
This code doesn't work.
Perhaps you just want a window function. I note that you are using left join in one place and the inner join is undoing it.
So, I am thinking:
SELECT c.*, i.*, u.*,
COUNT(*) OVER (PARTITION BY c.id) as category_cnt
FROM categories c LEFT JOIN LATERAL
(SELECT i.*
FROM influencer_profiles AS i
WHERE c.id = i.category_id
ORDER BY i.updated_at
LIMIT 2
) i
ON 1=1 LEFT JOIN
users u
ON i.user_id = u.id;
SELECT CONCAT(C.CUSTOMER_FNAME, ' ',C.CUSTOMER_LNAME) AS FullNAME, SUM(QTY* PRICE)AS TOTAL_SPENDINGS
FROM (SELECT DISTINCT TOP 2 TOTAL_SPENDINGS) RESULT
Customers$ C INNER JOIN Invoices$ Inv ON C.CUSTOMER_ID=Inv.CUSTOMER_ID
INNER JOIN InvDetails$ InvD ON Inv.INVOICE_ID=InvD.INVOICE_ID
INNER JOIN Products$ P ON P.PRODUCT_ID=InvD.PRODUCT_ID
GROUP BY C.CUSTOMER_FNAME,C.CUSTOMER_LNAME
ORDER BY TOTAL_SPENDINGS DESC
I am trying to prin the k-highest spending customers this is what i have done until now but i get
Incorrect syntax near 'Customers$'.
You are missing the join condition between the calculated table RESULT and the Customers table:
SELECT CONCAT(C.CUSTOMER_FNAME, ' ',C.CUSTOMER_LNAME) AS FullNAME, SUM(QTY* PRICE)AS TOTAL_SPENDINGS
FROM (SELECT DISTINCT TOP 2 TOTAL_SPENDINGS) RESULT
<missing INNER / LEFT join here>
Customers$ C <missing ON here> INNER JOIN Invoices$ Inv ON C.CUSTOMER_ID=Inv.CUSTOMER_ID
INNER JOIN InvDetails$ InvD ON Inv.INVOICE_ID=InvD.INVOICE_ID
INNER JOIN Products$ P ON P.PRODUCT_ID=InvD.PRODUCT_ID
GROUP BY C.CUSTOMER_FNAME,C.CUSTOMER_LNAME
ORDER BY TOTAL_SPENDINGS DESC
Example tables
taccount
tuser
tproject
What I want to achieve:
accountName count(u.id) count(p.id)
-----------------------------------
Account A 1 1
Account B 1 1
Account C 2 3
In other words I want a single query to join these tables together and count user's and project's per account
I tried:
SELECT
a.name as "accountName",
count(u.name),
count(p.id)
FROM "taccount" a
INNER JOIN "tuser" u ON u.account_id = a.id
INNER JOIN "tproject" p ON p.admin_id = u.id
GROUP BY u.name, a.name, p.id
But it's not grouping by account. It's giving me the following result
Any advice?
You can try below
SELECT
a.name as "accountName",
count(distinct u.name),
count(p.id)
FROM "taccount" a
INNER JOIN "tuser" u ON u.account_id = a.id
INNER JOIN "tproject" p ON p.admin_id = u.id
GROUP BY a.name
When you do Aggregate Function and If there are Column are not do Aggregate you must put in your Group By, because Aggregate functions perform a calculation on a set of rows and return a single row.
SELECT
a.name as "accountName",
count(distinct u.name),
count(p.id)
FROM
"taccount" a
INNER JOIN "tuser" u ON u.account_id = a.id
INNER JOIN "tproject" p ON p.admin_id = u.id
GROUP BY
a.name
So you need just Group By your column "accountName"
change your group by column name
SELECT
a.name as "accountName",
count(distinct u.account_id),
count(p.id)
FROM "taccount" a
INNER JOIN "tuser" u ON u.account_id = a.id
INNER JOIN "tproject" p ON p.admin_id = u.id
GROUP BY a.name
this will work:
select a.name,count(u.id),count(p.id) from
taccount a,tuser b, tproject where
a.id=b.account_id and
b.id=c.admin_id
group by a.name;
I have a table which has several one to many relationships with other tables. Let's say the main table is a person, and the other tables represent pets, cars and children. I would like a query that returns details of the person,the number of pets, cars and children they have e.g.
Person.Name Count(cars) Count(children) Count(pets)
John Smith 3 2 4
Bob Brown 1 3 0
What is the best way to do this?
Subquery Factoring (9i+):
WITH count_cars AS (
SELECT t.person_id
COUNT(*) num_cars
FROM CARS c
GROUP BY t.person_id),
count_children AS (
SELECT t.person_id
COUNT(*) num_children
FROM CHILDREN c
GROUP BY t.person_id),
count_pets AS (
SELECT p.person_id
COUNT(*) num_pets
FROM PETS p
GROUP BY p.person_id)
SELECT t.name,
NVL(cars.num_cars, 0) 'Count(cars)',
NVL(children.num_children, 0) 'Count(children)',
NVL(pets.num_pets, 0) 'Count(pets)'
FROM PERSONS t
LEFT JOIN count_cars cars ON cars.person_id = t.person_id
LEFT JOIN count_children children ON children.person_id = t.person_id
LEFT JOIN count_pets pets ON pets.person_id = t.person_id
Using inline views:
SELECT t.name,
NVL(cars.num_cars, 0) 'Count(cars)',
NVL(children.num_children, 0) 'Count(children)',
NVL(pets.num_pets, 0) 'Count(pets)'
FROM PERSONS t
LEFT JOIN (SELECT t.person_id
COUNT(*) num_cars
FROM CARS c
GROUP BY t.person_id) cars ON cars.person_id = t.person_id
LEFT JOIN (SELECT t.person_id
COUNT(*) num_children
FROM CHILDREN c
GROUP BY t.person_id) children ON children.person_id = t.person_id
LEFT JOIN (SELECT p.person_id
COUNT(*) num_pets
FROM PETS p
GROUP BY p.person_id) pets ON pets.person_id = t.person_id
you could use the COUNT(distinct x.id) synthax:
SELECT person.name,
COUNT(DISTINCT car.id) cars,
COUNT(DISTINCT child.id) children,
COUNT(DISTINCT pet.id) pets
FROM person
LEFT JOIN car ON (person.id = car.person_id)
LEFT JOIN child ON (person.id = child.person_id)
LEFT JOIN pet ON (person.id = pet.person_id)
GROUP BY person.name
I would probably do it like this:
SELECT Name, PersonCars.num, PersonChildren.num, PersonPets.num
FROM Person p
LEFT JOIN (
SELECT PersonID, COUNT(*) as num
FROM Person INNER JOIN Cars ON Cars.PersonID = Person.PersonID
GROUP BY Person.PersonID
) PersonCars ON PersonCars.PersonID = p.PersonID
LEFT JOIN (
SELECT PersonID, COUNT(*) as num
FROM Person INNER JOIN Children ON Children.PersonID = Person.PersonID
GROUP BY Person.PersonID
) PersonChildren ON PersonChildren.PersonID = p.PersonID
LEFT JOIN (
SELECT PersonID, COUNT(*) as num
FROM Person INNER JOIN Pets ON Pets.PersonID = Person.PersonID
GROUP BY Person.PersonID
) PersonPets ON PersonPets.PersonID = p.PersonID
Note, that it depends on your flavour of RDBMS, whether it supports nested selects like the following:
SELECT p.name AS name
, (SELECT COUNT(*) FROM pets e WHERE e.owner_id = p.id) AS pet_count
, (SELECT COUNT(*) FROM cars c WHERE c.owner_id = p.id) AS world_pollution_increment_device_count
, (SELECT COUNT(*) FROM child h WHERE h.parent_id = p.id) AS world_population_increment
FROM person p
ORDER BY p.name
IIRC, this works at least with PostgreSQL and MSSQL. Not tested, so your mileage may vary.
Using subselects not very good practice, but may be here it will be good
select p.name, (select count(0) from cars c where c.idperson = p.idperson),
(select count(0) from children ch where ch.idperson = p.idperson),
(select count(0) from pets pt where pt.idperson = p.idperson)
from person p
You could do this with three outer joins:
SELECT
Person.Name,
sum(case when cars.id is not null then 1 else 0 end) car_count,
sum(case when children.id is not null then 1 else 0 end) child_count,
sum(case when pets.id is not null then 1 else 0 end) pet_count
FROM
Person
LEFT OUTER JOIN
cars on
Person.id = cars.person_id
LEFT OUTER JOIN
children on
Person.id = children.person_id
LEFT OUTER JOIN
pets on
Person.id = pets.person_id
GROUP BY
Person.Name
I belive that Oracle now supports the case when syntax, but if not you could use a decode.
You'd need to include multiple count statements in the query. Off the top of my head,
SELECT p.Name, COUNT(DISTINCT t.Cars), COUNT(DISTINCT o.Children), Count(DISTINCT p.Pets)
FROM Person p
INNER JOIN Transport t ON p.ID = t.PersonID
LEFT JOIN Offspring o ON p.ID = o.PersonID
LEFT JOIN Pets p ON p.ID = o.OwnerID
GROUP BY p.Name
ORDER BY p.Name