I have the following table in Access 2010.
EQID Breaker Circuit Rating
1 A One 1000
2 A Two 1500
3 A Three 500
4 A Four 1000
5 B One 1500
6 B Two 2000
I want to create a query to Group by Breaker, and show the Minimum Rating and the associated Circuit for that rating. I understand how to do this without showing the Circuit for the Minimum rating.
My desired query result would be:
EQID Breaker Circuit Rating
1 A Three 500
2 B One 1500
Try this:
SELECT a.*
FROM table AS a
INNER JOIN (
SELECT Breaker, MIN(Rating) AS min_rating
FROM table
GROUP BY Breaker
) AS b
ON a.Breaker = b.Breaker AND
a.Rating = b.min_rating;
SQLFiddle: http://www.sqlfiddle.com/#!2/ea4fb/2
You can try below:
SELECT t.EQID, t.Breaker, t.Circuit, t.Rating
FROM test t
INNER JOIN
(
SELECT a.Breaker, MIN(a.Rating) AS Rating
FROM test a
GROUP BY Breaker
) AS tmp
ON tmp.Breaker = t.Breaker AND tmp.Rating = t.Rating;
Sql fiddle demo: http://sqlfiddle.com/#!2/fe796/19
Related
I have a table called 'users' that has the following structure:
id (PK)
campaign_id
createdAt
1
123
2022-07-14T10:30:01.967Z
2
1234
2022-07-14T10:30:01.967Z
3
123
2022-07-14T10:30:01.967Z
4
123
2022-07-14T10:30:01.967Z
At the same time I have a table that tracks clicks per user:
id (PK)
user_id(FK)
createdAt
1
1
2022-07-14T10:30:01.967Z
2
2
2022-07-14T10:30:01.967Z
3
2
2022-07-14T10:30:01.967Z
4
2
2022-07-14T10:30:01.967Z
Both of these table are up to millions of records... I need the most efficient query to group the data per campaign_id.
The result I am looking for would look like this:
campaign_id
total_users
total_clicks
123
3
1
1234
1
3
I unfortunately have no idea how to achieve this while minding performance and most important of it all I need to use WHERE or HAVING to limit the query in a certain time range by createdAt
Note, PostgreSQL is not my forte, nor is SQL. But, I'm learning spending some time on your question. Have a go with INNER JOIN after two seperate SELECT() statements:
SELECT * FROM
(
SELECT campaign_id, COUNT (t1."id(PK)") total_users FROM t1 GROUP BY campaign_id
) tbl1
INNER JOIN
(
SELECT campaign_id, COUNT (t2."user_id(FK)") total_clicks FROM t2 INNER JOIN t1 ON t1."id(PK)" = t2."user_id(FK)" GROUP BY campaign_id
) tbl2
USING(campaign_id)
See an online fiddle. I believe this is now also ready for a WHERE clause in both SELECT statements to filter by "createdAt". I'm pretty sure someone else will come up with something better.
Good luck.
Hope this will help you.
select u.campaign_id,
count(distinct u.id) users_count,
count(c.user_id) clicks_count
from
users u left join clicks c on u.id=c.user_id
group by 1;
See here query output
I have two tables - StepModels (support plan) and FeedbackStepModels (feedback), StepModels keeps how many steps each support plan requires.
SELECT [SupportPlanID],COUNT(*)AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
SupportPlanID (Steps)
-------------------------------
1 4
2 9
3 3
4 10
FeedbackStepModels keeps how many steps employee entered the system
SELECT [FeedbackID],SupportPlanID,Count(*)AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,SupportPlanID
FeedbackID SupportPlanID
---------------------------------------------
1 1 3 --> this suppose to be 4
2 2 9 --> Correct
3 3 0 --> this suppose to be 3
4 4 10 --> Correct
If submitted Feedback steps total is less then required total amount I want to delete this wrong entry from the database. Basically i need to delete FeedbackID 1 and 3.
I can load the data into List and compare and delete it, but want to know if we can we do this in SQL rather than C# code.
You can use the query below to remove your unwanted data by SQL Script
DELETE f
FROM FeedbackStepModels f
INNER JOIN (
SELECT [FeedbackID],SupportPlanID, Count(*) AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,SupportPlanID
) f_derived on f_derived_FeedbackID=f.FeedBackID and f_derived.SupportPlanID = f.SupportPlanID
INNER JOIN (
SELECT [SupportPlanID],COUNT(*)AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
) s_derived on s_derived.SupportPlanID = f.SupportPlanID
WHERE f_derived.StepsNumber < s_derived.Steps
I think you want something like this.
DELETE FROM [FeedbackStepModels]
WHERE FeedbackID IN
(
SELECT a.FeedbackID
FROM
(
SELECT [FeedbackID],
SupportPlanID,
COUNT(*) AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,
SupportPlanID
) AS a
INNER JOIN
(
SELECT [SupportPlanID],
COUNT(*) AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
) AS b ON a.SupportPlanID = b.[SupportPlanID]
WHERE a.StepsNumber < b.Steps
);
Probably the wrong title, but I can't summarise what I'm trying to do nicely. Which is probably why my googling hasn't helped.
I have a list of Discounts, and a list of TeamExclusiveDiscounts (DiscountId, TeamId)
I call a stored procedure passing in #TeamID (int).
What I want is all Discounts except if they're in TeamExclusiveDiscounts and don't have TeamID matching #TeamId.
So the data is something like
Table Discount:
DiscountID Name
-----------------------
1 Test 1
2 Test 2
3 Test 3
4 Test 4
5 Test 5
Table TeamExclusiveDiscount:
DiscountID TeamID
-----------------------
1 10
2 10
2 4
3 8
Expected results:
searching for TeamID = 10 I should get discounts 1,2,4,5
searching for TeamID = 5 I should get discounts 4, 5
searching for TeamID = 8 I should get discounts 3, 4, 5
I've tried a variety of joins, or trying to update a temp table to set whether the discount is allowed or not, but I just can't seem to get my head around this issue.
So I'm after the T-SQL for my stored procedure that will select the correct discounts (SQL Server). Thanks!
SELECT D.DiscountID FROM Discounts D
LEFT JOIN TeamExclusiveDiscount T
ON D.DiscountID=T.DiscountID
WHERE T.TeamID=#TeamID OR T.TeamID IS NULL
SQLFIDDLE for TEST
Can you try this - it only selects records where there is a teamdiscount record with the team or no teamdiscount record at all.
SELECT * FROM Discounts D
WHERE
EXISTS (
SELECT 1
FROM TeamExclusiveDiscount T
WHERE T.DiscountID = D.DiscountID
AND TeamID = #TeamID
)
OR
NOT EXISTS (
SELECT 1
FROM TeamExclusiveDiscount T
WHERE T.DiscountID = D.DiscountID
)
I like to translate the English description directly into SQL (atleast as a first pass):
"All Discounts except if they're in TeamExclusiveDiscounts and don't have TeamID matching #TeamId."
SELECT *
FROM Discounts D -- All Discounts
WHERE D.DiscountID NOT IN -- except if they're in TeamExclusiveDiscounts
(SELECT T.DiscountID
FROM TeamExclusiveDiscount T
WHERE T.DiscountID NOT IN -- and don't have TeamID matching #TeamId.
(SELECT Match.DiscountID
FROM TeamExclusiveDiscount Match
WHERE Match.TeamID = #TeamID)
)
After many attempts I have failed at this and hoping someone can help. The query returns every entry a user makes when items are made in the factory against and order number. For example
Order Number Entry type Quantity
3000 1 1000
3000 1 500
3000 2 300
3000 2 100
4000 2 1000
5000 1 1000
What I want to the query do is to return filter the results like this
If the order number has an entry type 1 and 2 return the row which is type 1 only
otherwise just return row whatever the type is for that order number.
So the above would end up:
Order Number Entry type Quantity
3000 1 1000
3000 1 500
4000 2 1000
5000 1 1000
Currently my query (DB2, in very basic terms looks like this ) and was correct until a change request came through!
Select * from bookings where type=1 or type=2
thanks!
select * from bookings
left outer join (
select order_number,
max(case when type=1 then 1 else 0 end) +
max(case when type=2 then 1 else 0 end) as type_1_and_2
from bookings
group by order_number
) has_1_and_2 on
type_1_and_2 = 2
has_1_and_2.order_number = bookings.order_number
where
bookings.type = 1 or
has_1_and_2.order_number is null
Find all the orders that have both type 1 and type 2, and then join it.
If the row matched the join, only return it if it is type 1
If the row did not match the join (has_type_2.order_number is null) return it no matter what the type is.
A "common table expression" [CTE] can often simplify your logic. You can think of it as a way to break a complex problem into conceptual steps. In the example below, you can think of g as the name of the result set of the CTE, which will then be joined to
WITH g as
( SELECT order_number, min(type) as low_type
FROM bookings
GROUP BY order_number
)
SELECT b.*
FROM g
JOIN bookings b ON g.order_number = b.order_number
AND g.low_type = b.type
The JOIN ON conditions will work so that if both types are present then low_type will be 1, and only that type of record will be chosen. If there is only one type it will be identical to low_type.
This should work fine as long as 1 and 2 are the only types allowed in the bookings table. If not then you can simply add a WHERE clause in the CTE and in the outer SELECT.
database table like this
============================
= suburb_id | value
= 1 | 2
= 1 | 3
= 2 | 4
= 3 | 5
query is
SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id
however, while I run this query, it doesn't give COUNT(suburb_id) = 0 when suburb_id = 0
because in suburbs table, there is no suburb_id 4, I want this query to return 0 for suburb_id = 4, like
============================
= total | suburb_id
= 2 | 1
= 1 | 2
= 1 | 3
= 0 | 4
A GROUP BY needs rows to work with, so if you have no rows for a certain category, you are not going to get the count. Think of the where clause as limiting down the source rows before they are grouped together. The where clause is not providing a list of categories to group by.
What you could do is write a query to select the categories (suburbs) then do the count in a subquery. (I'm not sure what MySQL's support for this is like)
Something like:
SELECT
s.suburb_id,
(select count(*) from suburb_data d where d.suburb_id = s.suburb_id) as total
FROM
suburb_table s
WHERE
s.suburb_id in (1,2,3,4)
(MSSQL, apologies)
This:
SELECT id, COUNT(suburb_id)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
LEFT JOIN
suburbs s
ON s.suburb_id = ids.id
GROUP BY
id
or this:
SELECT id,
(
SELECT COUNT(*)
FROM suburb
WHERE suburb_id = id
)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
This article compares performance of the two approaches:
Aggregates: subqueries vs. GROUP BY
, though it does not matter much in your case, as you are querying only 4 records.
Query:
select case
when total is null then 0
else total
end as total_with_zeroes,
suburb_id
from (SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id) as dt
#geofftnz's solution works great if all conditions are simple like in this case. But I just had to solve a similar problem to generate a report where each column in the report is a different query. When you need to combine results from several select statements, then something like this might work.
You may have to programmatically create this query. Using left joins allows the query to return rows even if there are no matches to suburb_id with a given id. If your db supports it (which most do), you can use IFNULL to replace null with 0:
select IFNULL(a.count,0), IFNULL(b.count,0), IFNULL(c.count,0), IFNULL(d.count,0)
from (select count(suburb_id) as count from suburbs where id=1 group by suburb_id) a,
left join (select count(suburb_id) as count from suburbs where id=2 group by suburb_id) b on a.suburb_id=b.suburb_id
left join (select count(suburb_id) as count from suburbs where id=3 group by suburb_id) c on a.suburb_id=c.suburb_id
left join (select count(suburb_id) as count from suburbs where id=4 group by suburb_id) d on a.suburb_id=d.suburb_id;
The nice thing about this is that (if needed) each "left join" can use slightly different (possibly fairly complex) query.
Disclaimer: for large data sets, this type of query might have not perform very well (I don't write enough sql to know without investigating further), but at least it should give useful results ;-)