I have four tables detailing an amusement park and its guests' ride history.
Categories
c_id name
1 Thrill
2 Leisure
3 Kiddie
Rides
r_id c_id
1 1
2 1
3 2
4 2
5 3
6 3
guest_history
h_id g_id
1 1
2 1
3 2
4 3
history_items
h_id r_id
1 5
2 6
3 1
3 2
4 5
How would I get all of the guests (g_id's) that have either rode all of the kiddie rides or none of the kiddie rides?
Expected Output would be:
g_id
1
2
I can't seem to figure out what the easiest way to go about it would be. I can only seem to conjure up a table that contains all of the cases that a guest has rode a kiddie ride. My attempt was a 4-way inner join of the tables and to filter out on the c_id = "Kiddie". Any help would be appreciated.
You can try this below logic-
3 is fixed in the query to get category "Kiddie"
DEMO HERE
SELECT A.g_id,COUNT(C.r_id)
FROM guest_history A
INNER JOIN history_items B ON A.h_id = B.h_id
INNER JOIN Rides C ON B.r_id = C.r_id AND C.c_id = 3
GROUP BY A.g_id
HAVING COUNT(DISTINCT B.r_id) = (SELECT COUNT(r_id) FROM Rides WHERE c_id = 3)
OR COUNT(DISTINCT B.r_id) = 0
SELECT g_id
FROM Categories
NATURAL JOIN Rides
NATURAL JOIN guest_history
NATURAL JOIN history_items
GROUP BY g_id
HAVING COUNT(DISTINCT r_id) IN (0,
(SELECT COUNT(DISTINCT r_id)
FROM Categories
NATURAL JOIN Rides
WHERE name = 'Kiddie')
)
fiddle
Related
I have persons i one table [person] and cars [car] registered to each person i another, connected by id.
I want to get a list of how many persons having how many cars.
Something like this:
PERSON
id
name
1
LISA
2
ADAM
3
RAY
CARS
id
id_person
brand
1
3
FORD
2
1
BMW
3
2
VOLVO
4
1
VOLVO
5
1
VW
RESULT
no cars
no persons
1
2
2
0
3
1
Just dont get how to do it?
You need to do it in two stages. The first is to get the number of cars per person -
SELECT p.id, COUNT(*) num_cars
FROM person p
JOIN cars c ON p.id = c.id_person
GROUP BY p.id
This can then be nested to count people per count -
SELECT num_cars, COUNT(*) num_people
FROM (
SELECT p.id, COUNT(*) num_cars
FROM person p
JOIN cars c ON p.id = c.id_person
GROUP BY p.id
) t
GROUP BY num_cars
ORDER BY num_cars ASC
I am currently working on a project while trying to learn MySQL and I would like to join three tables and get the latest status for each related shipment. Here are the tables I'm working with (with example data):
shipments
id
consignee
tracking_number
shipper
weight
import_no
1
JOHN BROWN
TBA99900000121
AMAZON
1
101
2
HELEN SMITH
TBA99900000190
AMAZON
1
102
3
JACK BLACK
TBA99900000123
AMAZON
1
103
4
JOE BROWM
TBA99900000812
AMAZON
1
104
5
JULIA KERR
TBA99900000904
AMAZON
1
105
statuses
id
name
slug
1
At Warehouse
at_warehouse
2
Ready For Pickup
ready_for_pickup
3
Delivered
delivered
shipment_status (pivot table)
id
shipment_id
status_id
1
1
1
2
2
1
3
3
1
4
4
1
5
5
1
6
1
2
7
2
2
8
3
2
9
4
2
10
5
2
all tables do have created_at and updated_at timestamp columns
Example of the results I'm trying to achieve
slug
shipment_id
status_id
ready_for_pickup
1
2
ready_for_pickup
2
2
ready_for_pickup
3
2
ready_for_pickup
4
2
ready_for_pickup
5
2
Here's the query I wrote to try to achieve what I'm looking for based on examples and research I did during the past couple of days. I find that sometimes there is sometimes a mismatch with the latest status that relates to the shipment
SELECT
statuses.slug AS slug,
MAX(shipments.id) AS shipment_id,
statuses.id AS status_id,
FROM
`shipments`
INNER JOIN `shipment_status` ON `shipment_status`.`shipment_id` = `shipments`.`id`
INNER JOIN `statuses` ON `shipment_status`.`status_id` = `statuses`.`id`
GROUP BY
`shipment_id`
Because we need to reference other fields from the same record that evaluates from the MAX aggregation, you need to do it in two steps, there are other ways, but I find this syntax simpler:
SELECT
shipments.id AS id,
statuses.slug AS slug,
statuses.id AS status_id,
shipment_status.shipment_id as shipment_id
FROM
`shipments`
INNER JOIN `shipment_status` ON `shipment_status`.`shipment_id` = `shipments`.`id`
INNER JOIN `statuses` ON `shipment_status`.`status_id` = `statuses`.`id`
WHERE
shipment_status.id = (
SELECT MAX(shipment_status.id)
FROM `shipment_status`
WHERE shipment_status.shipment_id = shipments.id
)
try it out!
This query makes the assumption that the id field is an identity column, so the MAX(shipment_status.id) represents only the most recent status for the given shipment_id
You can use window functions:
SELECT s.id, st.slug, st.id
FROM shipments s JOIN
(SELECT ss.*,
ROW_NUMBER() OVER (PARTITION BY shipment_id ORDER BY ss.id DESC) as seqnum
FROM shipment_status ss
) ss
ON ss.shipment_id = s.id JOIN
statuses st
ON ss.status_id` = st.id
WHERE ss.seqnum = 1;
Also note the use of table aliases so the query is easier to write and to read.
I have a table order_detail with this informations
id_order id_product
1 2
1 3
2 2
2 4
2 5
2 3
3 2
3 1
4 2
4 3
4 1
4 6
I would like to get most sold products(the first 5 elements) with the current product let's say product id 2
I tried this but it returns one wrong result
SELECT od2.product_id, count(od2.`product_id`) FROM `ps_order_detail` od1
LEFT JOIN ps_order_detail od2 ON od1.id_order = od2.id_order where
od2.product_id != od1.product_id AND od1.product_id=2
The result should be
product_id count(od2.`product_id`)
3 3
4 2
1 1
5 1
6 1
Your query is on the right track. Mostly, you are missing a group by:
select od.product_id, count(od2.id_order) as NumTimesWith2
from ps_order_detail od left join
ps_order_detail od2
on od.id_order = od2.id_order and
od2.product_id = 2
where od.product_id <> 2
group by od.product_id
order by count(od2.id_order) desc;
If you want only one such product, then add a limit 1 to the query.
Also, this assumes that products are not repeated inside orders. If they can be, you can quickly get a better count using count(distinct od.id_order)).
I have two tables:
LLOAN
LOANID SOURCEID LOAN_COMPANY ETC
1 1 3
2 1 3
3 1 1
4 2 1
5 2 1
6 2 1
7 3 1
8 3 1
COMPANY
CompanyID CountryID CompanyIDLLAS
1 1 1
2 1 2
3 1 3
4 2 1
5 3 1
6 4 1
And I want to join them. The SourceID refers to the CountryID and the LOAN_COMPANY refers to the CompanyID. Only country '1' has multiple companies, all the others just have one.
How can I join these two tables correctly? I've tried many different things, of which this came the closest:
SELECT Count(c.CompanyID) FROM dbo.LLOAN As l
LEFT JOIN dbo.Company As c ON c.CountryID = l.SourceID AND c.CompanyID = l.LOAN_COMPANY
But it leaves many rows blank. What is the correct way to join two tables with two conditions?
Try below Query:
SELECT Count(c.CompanyID)
FROM dbo.LLOAN As LL
LEFT JOIN dbo.Company As C
ON (C.CountryID = LL.SourceID)
AND (C.CompanyID = LL.LOAN_COMPANY)
You can group the condition using paranthesis like this:
SELECT Count(c.CompanyID)
FROM dbo.LLOAN As l
LEFT JOIN dbo.Company As c ON (c.CountryID = l.SourceID) AND (c.CompanyID = l.LOAN_COMPANY)
I have two tables -
Users_tag (userID,tagID)
tagId - userId
1 1
2 1
3 2
4 2
5 4
Tags (id,tagText)
id tagText
1 dog
2 cat
3 lion
4 tiger
5 chicken
I want my query to return tagId,TagText and count of each row based on userId.
Any help please...
SELECT a.id, a.tagText, COUNT(b.tagID) totalCount
FROM Tags a
LEFT JOIN users_tag b
on a.ID = b.tagID
GROUP BY a.id, a.tagText
SQLFiddle Demo