Table WORK
(WORK ID, TITLE, DESCRIPTION, ARTIST ID)
Table ARTIST
(ARTIST ID, FIRSTNAME, LAST NAME, DATE OF BIRTH, DATE OF DEATH)
Hi
My problem is that I have to display the details of all works of art (including the name of the artist who created the work) that are signed.
I managed to go until
Select * from Work WHERE DESCRIPTION LIKE '%Signed%'
and it displays
WorkID TITLE DESCRIPTION ARTISTID
123 1455 Signed 12
However, I must display
WorkID TITLE DESCRIPTION ARTISTID FIRSTNAME LASTNAME
123 1455 Signed 12
How do I do that? I know it has something to do with JOIN but I'm not very sure.
Inner Join will do or can try left join if u need to
SELECT W.*, A.FirstNAme, A.LastName from work w inner join Artist A on
A.Artistid
= W.ArtistId where A.Description LIKE '%Signed%'
Use inner join to get the records that exist in both tables
Select W.WorkID, W.TITLE, W.DESCRIPTION, W.ARTISTID, A.FIRSTNAME, A.LASTNAME
From Work W
Inner Join Artist A on W.WorkID = A.WorkID
Where Description LIKE '%Signed%'
a left outer join would get all the records in the work table and the matching ones in the artist table.
Check this post out to understand joins a bit more : JOINS
Related
I have these tables with the following column names:
players:
id first_name last_name age position salary hire_date skills_data_id team_id
Skills:
id, dribbling, pace, passing, shooting, speed, strength
towns:
id, name, country_id
teams:
id name established fan_base stadium_id
On this base, I have found the players with the max speed in terms of towns where their team played.
At the same time, I have to skip players that played in team ‘Devify’.
At the moment I have tried with this code, but the final result is not correct.
select max(s.speed) as `max_speed`,tt.name as `town_name`
from skills_data as s
right join players as p on s.id = p.skills_data_id
inner join teams as t on p.team_id = t.id
inner join towns as tt on p.team_id = tt.id
where t.name not like 'Devify'
group by s.id
order by max(s.speed) desc, town_name;
The result should be something like that:
max_speed town_name
97 Smolensk
92 Bromma
92 Lühua
...
NULL Zavolzh’ye
My result is:
max_speed town_name
97 Montréal-Ouest
92 Dalubian
92 Samsan
Thank you in advance.
There is a problem in your group by clause: you should be grouping by town rather than by skill id.
I am also quite suspicious about the join condition that brings in the towns (see my comment under your question): but if you are getting results for your existing query, it must be right...
Other changes to your query:
changed your right join to an inner join
used more meaningful table aliases
used an inequality condition instead of not like to exclude the unwanted team
New query:
select
max(sk.speed) as max_speed,
to.name as `town_name`
from skills_data as sk
inner join players as pl on sk.id = pl.skills_data_id
inner join teams as te on pl.team_id = te.id and te.name <> 'Devify'
inner join towns as to on pl.team_id = to.id
group by to.id, to.name
order by max_speed desc, town_name;
I'm using an example database I got through DBeaver. It contains a table called Artists and a table called Albums. Some artists have no albums, some have one and some have many.
What I'm trying to achieve is a left join to show all artists but only display the album name of the artists who only have one album.
The following works using DBeaver but doesn't work if executed directly from MS Access (which i need to be able to do):
SELECT
ar.AName,
al.title
FROM
Artist ar
LEFT JOIN (
SELECT
al.*
FROM
album al
INNER JOIN (
SELECT
artistid,
COUNT( artistid ) artistCount
FROM
album
GROUP BY
artistid ) alc ON
alc.artistid = al.artistid
AND alc.artistcount = 1 ) al ON
al.artistid = ar.artistid
ORDER BY
ar.aname
Tables have the following columns:
Artist
ArtistID (Key)
Name
Album
AlbumID (Key)
Title
ArtistID
Many thanks in advance. I can't find an answer to this anywhere. I understand the version of SQL used in MS Access isn't the same as found in various other variants.
Cheers
Patrick
I would go with NOT EXISTS :
SELECT a.ArtistID, a.Name, al.Title
FROM Artist a LEFT JOIN
Album al
ON al.ArtistID = a.ArtistID AND
NOT EXISTS (SELECT 1
FROM Album al1
WHERE al1.ArtistID = al.ArtistID AND a1l.AlbumID <> al.AlbumID
);
Thank you for your help. I have managed to produce the results I was expecting using SQL in MS Access (will need to test to ensure its 100%).
I used the following:
SELECT
ar.AName,
al.title
FROM
Artist ar
LEFT JOIN (
SELECT
al.*
FROM
album al,
(
SELECT
al1.artistid,
COUNT( al1.artistid ) AS al1Count
FROM
album al1
GROUP BY
al1.artistid ) al1
WHERE
al.artistID = al1.artistid
AND al1.al1count = 1 ) al ON
al.artistid = ar.artistid
ORDER BY
ar.aname
Thanks again!
You don't want a left join. If an artist has exactly one album, then a regular join will work. The key is aggregation:
select ar.aname, max(al.title) as title
from artist as ar inner join
album as al
on ar.artistid = al.artistid
group by ar.artistid, ar.aname -- I supposed two artists could have the same name
having count(*) = 1;
The key idea is that if there is only one album, then max(al.title) returns that album's name.
EDIT: (based on comment)
select ar.aname,
switch(al.artistid is null, "No album"
count(*) = 1, max(al.title),
1=1, "> 1"
) as album_title
from artist as ar left join
album as al
on ar.artistid = al.artistid
group by ar.artistid, ar.aname;
My school task was to get names from my movie database actors which play in movies with highest ratings
I made it this way and it works :
select name,surname
from actor
where ACTORID in(
select actorid
from actor_movie
where MOVIEID in (
select movieid
from movie
where RATINGID in (
select ratingid
from rating
where PERCENT_CSFD = (
select max(percent_csfd)
from rating
)
)
)
);
the output is :
Gary Oldman
Sigourney Weaver
...but I'd like to also add to this select mentioned movie and its rating. It accessible in inner selects but I don't know how to join it with outer select in which i can work just with rows found in Actor Table.
Thank you for your answers.
You just need to join the tables properly. Afterwards you can simply add the columns you´d like to select. The final select could be looking like this.
select ac.name, ac.surname, -- go on selecting from the different tables
from actor ac
inner join actor_movie amo
on amo.actorid = ac.actorid
inner join movie mo
on amo.movieid = mo.movieid
inner join rating ra
on ra.ratingid = mo.ratingid
where ra.PERCENT_CSFD =
(select max(percent_csfd)
from rating)
A way to get your result with a slightly different method could be something like:
select *
from
(
select name, surname, percent_csfd, row_number() over ( order by percent_csfd desc) as rank
from actor
inner join actor_movie
using (actorId)
inner join movie
using (movieId)
inner join rating
using(ratingId)
(
where rank = 1
This uses row_number to evaluate the "rank" of the movie(s) and then filter for the movie(s) with the highest rating.
I have a table like this
ID|list
1|:A:B:C:
2|:B:D:A:
3|:C:A:D:
I want to count the number of each of A,B,C,D and group them as
A|3
B|2
C|2
D|2
I was thinking about iterating through the table and inserting values in to a temporary table from count statements like the following
select count(*) from table where list like %:A:%
It does look ugly.Is there a better way to do this?
(I am using sqlite from qt)
Never, never, never store multiple values in one column! A better DB design would be
movies table
----------
id
name
release_date
...
actors table
------------
id
first_name
last_name
birth_date
...
movie_cast table
----------------
movie_id
actor_id
You could then select all actors of a specific movie like this
select a.lastName, a.first_name
from actors a
join movie_cast c on c.actor_id = a.id
join movies m on c.movie_id = m.id
where m.name = 'Citizen Kane'
Or select all movies a specific actor stars in like this
select m.name
from actors a
join movie_cast c on c.actor_id = a.id
join movies m on c.movie_id = m.id
where a.lastName ='Wayne'
and a.first_name 'John'
Database Structure
MovieInfo (mvID, title, rating, year, length, studio)
DirectorInfo(directorID, firstname, lastname)
MemberInfo(username, email, password)
ActorInfo(actorID, firstname, lastname, gender, birthplace)
CastInfo(mvID*, actorID*)
DirectInfo(mvID*, directorID*)
GenreInfo(mvID*, genre)
RankingInfo(username*, mvID*, score, voteDate)
Query
I need to get the director with the largest number of comedy movies. (I'm also required to use the ALL operator). My understanding is getting the list of mvid where genre = 'Comedy" and directorid:
select mvid
from genreinfo
where genre = 'Comedy'
union all
select directorid
from directorinfo
;
But then how do I count the number of movies a specific director has? And how do I get that single one with the highest count of "comedy" movies?
You're on the right track. I'd recommend looking at JOINs.
I've provided a step-by-step answer on how to obtain the desired results. If you just want the final query, go down to step 5 and pick the one appropriate for your DBMS.
1: Selecting all comedy movie IDs:
SELECT mvid
FROM GenreInfo
WHERE genre = 'Comedy';
2: Selecting the directorIDs of those movies
SELECT directorID
FROM DirectInfo
JOIN GenreInfo
ON DirectInfo.mvID = GenreInfo.mvID
WHERE genre = 'Comedy';
3: Selecting the director name of those directors.
SELECT firstname
FROM DirectorInfo
JOIN DirectInfo
ON DirectorInfo.directorID = DirectInfo.directorID
JOIN GenreInfo
ON DirectInfo.mvID = GenreInfo.mvID
WHERE genre = 'Comedy';
4: Grouping that query by director to get number of movies:
SELECT firstname, COUNT(*) AS NumberOfMovies
FROM DirectorInfo
JOIN DirectInfo
ON DirectorInfo.directorID = DirectInfo.directorID
JOIN GenreInfo
ON DirectInfo.mvID = GenreInfo.mvID
WHERE genre = 'Comedy'
GROUP BY DirectorInfo.directorID;
5: Sort the results and get only the first one:
SELECT firstname, COUNT(*) AS NumberOfMovies
FROM DirectorInfo
JOIN DirectInfo
ON DirectorInfo.directorID = DirectInfo.directorID
JOIN GenreInfo
ON DirectInfo.mvID = GenreInfo.mvID
WHERE genre = 'Comedy'
GROUP BY DirectorInfo.directorID
ORDER BY NumberOfMovies
LIMIT 1;
If you're using SQL server, use TOP instead:
SELECT TOP 1 firstname, COUNT(*) AS NumberOfMovies
FROM DirectorInfo
JOIN DirectInfo
ON DirectorInfo.directorID = DirectInfo.directorID
JOIN GenreInfo
ON DirectInfo.mvID = GenreInfo.mvID
WHERE genre = 'Comedy'
GROUP BY DirectorInfo.directorID
ORDER BY NumberOfMovies;
You can use a join and group by to get the result.
select DirectorID,COUNT(mvid)
from DirectInfo d
inner join genreinfo g
ON d.mvid=g.mvid
where genre ='Comedy'
GROUP BY DirectorID
ORDER BY COUNT(mvid)
This is homework? Well, right now you are selecting a list of IDs, some of them representing directors, others representing movies. You notice that this is not at all what you are supposed to do, right?
What you want is a list of directors. So you select from the DirectorInfo table. You also want information about his movies (excatly: the number of movies of a certain kind). So you must join that information from MovieInfo. Now think about what else you need to glue together to get from director to their movies. Then think about how to glue in that genre criterium.
Once you have joined it all together, then you group your results. You want one record per director (instead of ane record per director and movie), so you make a group and count within that group.
I hope this helps you solve your task. Good luck!
select di.directorid, count(1) as 'no_of_comedy_movies'
from DirectorInfo di inner join join DirectInfo dri
on di.directorid = dri.directorid
inner join genreinfo gi
on gi.mvid = dri.mvid
where gi.genre = 'Comedy'
group by dri.directorID
order by no_of_comedy_movies