i am quite new in sqlite.
I have 2 tables (tableA, tableB) with the exact same schema.
id | CAT | country
They track the number of items per country on a special SW release
I would like to create a query that compares the count of rows per country on tableA and tableB where CAT = "AAA" on a single result like:
COUNTRY |count_tableA |count_tableB|
ARG |12 |16 |
BRA |23 |33 |
I can achieve it in separate tables but not in a single one.
Seperate table example:
select COUNTRY, count(*) as count_tableA from tableA WHERE CAT ="AAA" GROUP BY COUNTRY
select COUNTRY, count(*) as count_tableB from tableB WHERE CAT ="AAA" GROUP BY COUNTRY
Thanks for the help
One way to do it is use conditional aggregation on the UNION of the 2 tables:
select country,
sum(tablename = 'a') count_tableA,
sum(tablename = 'b') count_tableB
from (
select 'a' tablename, id, cat, country from tableA
union all
select 'b' tablename, id, cat, country from tableB
)
where cat = 'AAA'
group by country
You can use WITH and COUNT:
with t1 as (select country, count(*) as c1 from tableA where cat = 'AAA' group by country),
t2 as (select country, count(*) as c1 from tableB where cat = 'AAA' group by country)
select a1.country,
ifnull((select t1.c1 from t1 where t1.country = a1.country), 0) as count_tableA,
ifnull((select t2.c1 from t2 where t2.country = a1.country), 0) as count_tableB from (
select distinct country from tableA where cat = 'AAA'
union
select distinct country from tableB where cat = 'AAA'
) a1
group by country
Related
I'm very new to learning SQL, I apologize if my question isn't completely accurate.
The question I'm trying to answer with this query is "What is the most popular music genre in each country?" I've had to use a subquery and it works, but I found that for a few countries in the table, more than one genre has the MAX value. I'm stuck with how to edit my query so that all genres with the max value show in the results. Here is my code, using DB Browser for SQLite:
SELECT BillingCountry AS Country , name AS Genre , MAX(genre_count) AS Purchases
FROM (
SELECT i.BillingCountry, g.name, COUNT(g.genreid) AS genre_count
FROM Invoice i
JOIN InvoiceLine il
ON il.InvoiceId = i.InvoiceId
JOIN TRACK t
ON il.trackid = t.TrackId
JOIN Genre g
ON t.genreid = g.GenreId
GROUP BY 1,2
) sub
GROUP BY 1
Here is an example of the result:
| Country | Genre |Purchase|
|---------|-------|--------|
|Agrentina| Punk | 9 |
|Australia| Rock | 22 |
BUT in running just the subquery to COUNT the purchases, Argentina has two Genres with 9 Purchases (the max number for that country). How do I adjust my query to include both and not just the first one in the row?
You can do it with RANK() window function:
SELECT BillingCountry, name, genre_count
FROM (
SELECT i.BillingCountry, g.name, COUNT(*) AS genre_count,
RANK() OVER (PARTITION BY i.BillingCountry ORDER BY COUNT(*) DESC) rnk
FROM Invoice i
INNER JOIN InvoiceLine il ON il.InvoiceId = i.InvoiceId
INNER JOIN TRACK t ON il.trackid = t.TrackId
INNER JOIN Genre g ON t.genreid = g.GenreId
GROUP BY i.BillingCountry, g.name
)
WHERE rnk = 1
This will return the ties in separate rows.
If you want 1 row for each country, you could also use GROUP_CONCAT():
SELECT BillingCountry, GROUP_CONCAT(name) AS name, MAX(genre_count) AS genre_count
FROM (
SELECT i.BillingCountry, g.name, COUNT(*) AS genre_count,
RANK() OVER (PARTITION BY i.BillingCountry ORDER BY COUNT(*) DESC) rnk
FROM Invoice i
INNER JOIN InvoiceLine il ON il.InvoiceId = i.InvoiceId
INNER JOIN TRACK t ON il.trackid = t.TrackId
INNER JOIN Genre g ON t.genreid = g.GenreId
GROUP BY i.BillingCountry, g.name
)
WHERE rnk = 1
GROUP BY BillingCountry
I would like to know if, and if yes, how I could accomplsh the following:
Lets say I have two tables:
Table A has two Columns: id, name
Table B columns: owner, argument
Now I am trying to find in table A all rows with specific name (animal) and use their ids to find it's argument value in table b. Those argument values are different ids in table a. So as a result I would like to get two columns. first has the id of the items who has the specific name (animal) I am looking for and second column has the name of the item which has the id that is argument of the initial ids.
table a (example)
id || name
1 || animal
2 || animal
3 || animal
4 || animal
15 || cat
16 || dog
17 || horse
18 || bird
...
table b (example)
owner || argument
1 || 15
2 || 16
3 || 17
4 || 18
...
result (example)
id || name
1 || cat
2 || dog
3 || horse
4 || bird
Thanks in advance for any hints / help.
Andreas
You need a double join from tablea to tableb and again doublea:
select
a.name ownwename,
t.name name
from tablea a
inner join tableb b
on b.owner = a.id
inner join tablea t
on t.id = b.argument
where a.name = 'animal'
See the demo
I believe the following will do what you want
SELECT owner, name FROM tableb JOIN tablea ON argument = id;
However, as using a subquery you could use :-
SELECT owner, (SELECT name FROM tablea WHERE argument = id) AS name FROM tableb;
Working Example :-
DROP TABLE If EXISTS tablea;
CREATE TABLE IF NOT EXISTS tablea (id INTEGER PRIMARY KEY, name TEXT);
INSERT INTO tablea (name) VALUES ('animal'),('animal'),('animal'),('animal'),('cat'),('dog'),('horse'),('bird'),
('animal'),('cat'),('dog'),('horse'),('bird'),('animal'),
('cat'),('dog'),('horse'),('bird') -- id's 15-18 inclusive
;
DROP TABLE IF EXISTS tableb;
CREATE TABLE IF NOT EXISTS tableb (owner INTEGER PRIMARY KEY, argument INTEGER);
INSERT INTO tableb (argument) VALUES(15),(16),(17),(18);
SELECT owner, name FROM tableb JOIN tablea ON argument = id;
SELECT owner, (SELECT name FROM tablea WHERE argument = id) AS name FROM tableb;
Results :-
and the second
I'm having probleme with a SQL request.
I have two tables:
main table is
Id | Name
1 | Name_1
2 | Name_2
keyword table
Id | _mainId | key
1 | 1 | kw1
2 | 1 | kw2
3 | 1 | kw3
4 | 2 | kw2
5 | 2 | kw4
I would like a request which return the Id and Name of the mane table with all the keywords selected
something like this :
SELECT DISTINCT(t1.Id), t1.Name
FROM main t1
INNER JOIN keywords t2 ON t2._Main = t1.Id
WHERE t2.keyword = 'kw2' AND t2.keyword = 'kw4';
In the query below, the subquery aliased as t2 identifies all IDs having both the keywords 'kw2' and 'kw4'. I then join the main table to this subquery to bring in the name information for those matching IDs.
SELECT t1.Id, t1.Name
FROM main t1
INNER JOIN
(
SELECT _mainId
FROM keywords
WHERE keyword IN ('kw2', 'kw4')
GROUP BY _mainId
HAVING COUNT(DISTINCT keyword) = 2
) t2
ON t1.Id = t2._mainId
Try this:
SELECT DISTINCT
t1.Id, t1.Name
FROM
main t1
INNER JOIN keywords t2 ON t2._mainId=t1.Id
WHERE
t2.key IN ('kw2', 'kw4');
I want to do the following in LINQ to SQL:
Select count(*) as count_1,
(select count(*) from tableName2) as count_2 FROM tableName
Where x = y
The result should be
Column 1 | column 2
--------------------
50 34
What you need to do is something like this:
select
(select count(*)
from tableName
where x = y) as count_1,
(select count(*)
from tableName2) as count_2
I would like to know whether it is possible to use a SELECT statement in SQLite to merge the data from two rows into one, similar to how is suggested in the SQL Server forum below.
Consider the scenario below which is based on SQL Server (taken from http://forums.aspfree.com/microsoft-sql-server-14/merge-the-two-rows-in-one-row-245550.html)
Given there is a table
Emp
ID | Name |
1 | x |
1 | P |
2 | y |
2 | Q |
3 | W |
We want the resulting data from the select statement to output:
Emp_Data
Id | Name-1 | Name-2 |
1 | x | P |
2 | y | Q |
3 | w | |
The answer in the post suggests the following SQL as a possible solution:
SELECT
a.ID,
[Name-1] = ISNULL((
SELECT TOP 1 Name
FROM emp
WHERE ID = a.ID),''),
[Name-2] = ISNULL((
SELECT TOP 1 b.Name
FROM emp b
WHERE b.ID = a.ID
AND Name NOT IN(
SELECT TOP 1 Name
FROM emp
WHERE ID = b.ID
)),'')
FROM emp a
GROUP BY a.ID
Using SQLite is it possible to generate the columns [Name-1] & [Name-2] using nested SELECT statements like we can do above in SQL Server?
SELECT
a.ID,
COALESCE(a.Name,'') as "Name-1",
COALESCE((SELECT b.Name FROM Emp b
WHERE b.ID = a.ID
AND b.rowid != a.rowid LIMIT 1),'') as "Name-2"
FROM emp a
GROUP BY a.ID
Doug's solution didn't work for me. The code below, however, did work for me but it's very slow...
SELECT
a.ID,
a.Name AS Name1,
(SELECT b.Name FROM Emp b
WHERE b.ID = a.ID
AND b.Name != a.Name LIMIT 1) AS Name2
FROM emp a
GROUP BY a.ID
try this:::
select id, group_concat(name) from emp group by id;
;)