I am trying to create a query that will list all books by the same author. Most of the list has only one book by one author, but I want the author that has multiple books listed in db to display those book for that author.
I have two tables:
Book - AuthorID, BkTitle, etc
Author - AuthorID, AuthFName, AuthLName
I want the result to be sorted by AuthLName and the report to consist of any books in db that have same authorid.
Example result wanted:
AUTHORID BKTITLE AUTHFNAME AUTHLNAME
--------- ----------------- ------------ -----------
504 KNIGHT FREEDOM Chris Feehan
504 KNIGHT SHOWDOWN Chris Feehan
Currently, I have the following code:
select AUTHORID, BKTITLE
from BOOK
where AUTHORID in
(select AUTHORID from
(select AUTHORID,
count(*) as BOOK_COUNT
from BOOK
group by AUTHORid
order by AUTHORid )
where BOOK_COUNT >= 2);
which gives:
AUTHORID BKTITLE
---------- --------------------
504 KNIGHT FREEDOM
504 KNIGHT SHOWDOWN
I need to find a way to get the information from the Author Table and add it in this.
This should do:
SELECT b.AUTHORID, b.BKTITLE, a.AUTHFNAME, a.AUTHLNAME
FROM BOOK b
INNER JOIN AUTHOR a
ON b.AUTHORID = a.AUTHORID
AND b.AUTHORID IN
(
SELECT AUTHORID
FROM BOOK
GROUP BY AUTHORID
HAVING COUNT(AUTHORID) > 1
)
ORDER BY a.AUTHLNAME, a.AUTHFNAME
How about this - updated to use a CTE (Common Table Expression) first to figure out which authors have more than one book in the database table BOOK, and then listing only those authors and their books:
;WITH AuthorsWithMoreThanOneBook AS
(
SELECT AUTHORID, BOOK_COUNT = COUNT(*)
FROM BOOK
GROUP BY AUTHORID
HAVING BOOK_COUNT > 1)
)
SELECT
b.AUTHORID, b.BKTITLE, a.AuthFName, a.AuthLName
FROM
BOOK b
INNER JOIN
AUTHOR a ON b.AuthorID = a.AuthorID
INNER JOIN
AuthorsWithMoreThanOneBook A2 ON a.AuthorID = A2.AuthorID
ORDER BY
a.AuthLName, a.AuthFName
Update: OK, you're using Oracle .... not sure (haven't used it in ages) - but can't you just extend your original query something like this:
select bk.AUTHORID, bk.BKTITLE, a.AUTHORFNAME, a.AUTHORLNAME
from BOOK AS bk
INNER JOIN AUTHOR AS a ON a.AUTHORID = bk.AUTHORID
where bk.AUTHORID in
(select AUTHORID from
(select AUTHORID,
count(*) as BOOK_COUNT
from BOOK
group by AUTHORid
order by AUTHORid )
where BOOK_COUNT >= 2);
Not sure if/how Oracle supports those table aliases (BOOK AS bk) - but I'm pretty sure it does support it some way or another....
You can do this with only one access to each table:
SELECT * FROM
(
SELECT AuthorID, BkTitle, AuthFName, AuthLName
,COUNT(*) OVER (PARTITION BY AuthorID)
AS c
FROM BOOK
JOIN AUTHOR USING (AuthorID)
)
WHERE c > 1;
Related
I have the following psql tables with the following columns:
Library:
library_id
Shelf:
shelf_id
library_id (Library foreign key)
forbidden = (boolean)
Author
author_id
shelf_id (Shelf foreign key)
number_pages_witten
Book
book_id
author_id (Author foreign key)
book_name
I need a query that retrieves the following back:
For library_id=5, get the list of book names from authors who have written the most pages per shelf, for all shelves that have "forbidden" = False
I have the following so far:
SELECT name FROM Book AS b
INNER JOIN Author AS a
ON b.author_id = a.author_id
...
...
WHERE library_id=5
My sql syntax is very weak. I'm having trouble getting the author with the most number of pages on the shelf back and plug it into rest of the query. Thank you.
The requirement to get "authors who have written the most pages per shelf, for all shelves that have "forbidden" = False" is a classic usecase for the rank() window function. From there on, you just need an inner queries:
SELECT name
FROM book b
WHERE b.author_id IN (SELECT author_id
FROM (SELECT a.author_id,
RANK() OVER
(PARTITION BY a.shelf_id
ORDER BY number_pages_written DESC) rk
FROM author a
JOIN shelf s ON a.shelf_id = a.shelf_id
WHERE library_id = 5)
WHERE rk = 1)
This query simultaneously retrieve list of most pages book per author and per shelf,
At first, It's prepared a list of Author Id, Shelf Id and Number Pages Written by a self-join that has the same Author Id and Shelf Id but their Number Pages Written are different,
Then, Group by Author Id and Shelf Id
I hope it can be helpful for your question and all relate issues
select author_id1, shelf_id1, max(num_pages1)
(
select
Author1.author_id author_id1, Author1.shelf_id shelf_id1, Author1.number_pages_witten num_pages1,
Author2.author_id author_id2, Author2.shelf_id shelf_id2, Author2.number_pages_witten num_pages2
from Author Author1 left join Author Author2
on Author1.author_id = Author2.author_id and Author1.shelf_id = Author2.shelf_id
and Author1.number_pages_witten != Author2.number_pages_witten
)ds
group by author_id1, shelf_id1
I have a table of books, a table of authors, and a "linker" table (many to many links between authors/books).
How do I find the authors with the highest number of books?
This is my schema:
books : rowid, name
authors : rowid, name
book_authors : rowid, book_id, author_id
This is what I came up with: (but it doesn't work)
SELECT count(*) IN book_authors
WHERE (SELECT count(*) IN book_authors
WHERE author_id = author_id)
And ideally I would like a report of the top 100 authors, something like:
author_name book_count
-----------------------------------
Johnny 25
Kelly 12
Ramboz 10
Do I need some kind of join? What is the fastest approach?
I'd join the three tables (via the book_authors table), group by the author, count occurrences and limit it to the top 100 rows:
SELECT a.name, COUNT(*)
FROM authors a
JOIN books_authors ba ON a.rowid = ba.author_id
JOIN books b ON ba.book_id = b.rowid
GROUP BY a.name
ORDER BY 2 DESC
LIMIT 100
EDIT:
Actually, we aren't using any data from books, just the fact the book actually exists, which can be inferred from books_authors, so this query can be improved by dropping the second join:
SELECT a.name, COUNT(*)
FROM authors a
JOIN books_authors ba ON a.rowid = ba.author_id
GROUP BY a.name
ORDER BY 2 DESC
LIMIT 100
Couldn't you just
select count(1) , Author_ID from Book_Authors group by Author_ID order by count(1) desc limit 100
The authors with the most books would be at the top (or the author_ID would be at least)
As for limiting to top 100... then add limit clause Sqlite LIMIT / OFFSET query
SELECT TOP 3 authors.author_name, authors.book_name, books.sold_copies,
(SELECT SUM(books.sold_copies) FROM books WHERE authors.book_name = books.book_name ) AS Total
FROM authors
INNER JOIN books
ON authors.book_name = books.book_name
ORDER BY sold_copies desc
I need one very expert help, I can't seem to find the answer to this, the problem is, find the titles and ISBNs of books that have the same title and publishers as at least 2 other books.
Order it by title.
So basically, everything is coming from the book table.
CREATE TABLE BOOK
(
ISBN VARCHAR2(20),
Title VARCHAR2(250) NOT NULL,
YearPublished NUMBER(4) NOT NULL,
PublisherName VARCHAR2(40) NOT NULL,
CONSTRAINT pk_isbnP PRIMARY KEY(ISBN)
);
Here is my rough draft:
select _____
from book b2
where ______ (select____ from book b2
where _____ = ______ and ______ =______)
Step 1: Find combinations of title and publisher that have at least 2 books:
SELECT title, PublisherName
FROM BOOK
GROUP BY title, PublisherName
HAVING COUNT(*) > 1
Step 2: find all other books that have this title and publisher:
SELECT *
FROM Books b1
WHERE EXISTS(
SELECT title, PublisherName
FROM BOOK b2
WHERE b1.title = b2.title AND b1.PublisherName = b2.PublisherName
GROUP BY title, PublisherName
HAVING COUNT(*) > 1
)
This ought to do it:
select isbn, title
from books
where (title,publishername) in(select title,publishername
from books
group by title,publishername
having count(*) >=3)
order by title;
select b1.title, b1.isbn
from book b1
inner join
(select title, publishername
from book
group by title, publishername having count(*) > 2) b2
on b1.title = b2.title and b1.publishername = b2.publishername
order by b1.title
The inner query fetches the titles/publishers of books where there are three or more duplicates. The outer query uses those results to get the associated ISBNs.
You can use group by statement here.
SELECT title
,isbn
FROM BOOKS
group by title, isbn
having COUNT(1) >= 2 order by title;
I have 2 tables: authors and books.
in authors i have attributes authorID, authorName, and authorDOB.
authorID is the primary key in this table.
in the books table i have attributes bookISBN, authorID, etc.
with bookISBN as the primary and authorID as the foreign key
i am trying to perform a query where given an author name, perform a
count of all the books by that author.
here is what i got:
SET #ID =
AuthorID
FROM authors
WHERE ('Mark Twain' = AuthorName);
SELECT COUNT(*)
FROM books
WHERE (AuthorID = ID);
Any help would be greatly appreciated
Try:
SELECT a.authorId, a.authorName, count(*)
FROM authors a
INNER JOIN books b ON b.AuthorID=a.AuthorID
WHERE ('Mark Twain' = a.AuthorName)
GROUP BY a.authorId, a.authorName
i am trying to perform a query where given an author name, perform a count of all the books by that author.
Try
select count(1)
from books b
inner join authors a on a.AuthorID=b.AuthorID
where a.AuthorName='Mark Twain'
You can use a function as well if you think you'd be doing the search more frequently. Just an idea.
go
create function totalbooksbyauthor (#authorname varchar(20) ) returns table
as return
select a.authorid, a.authorname, COUNT(b.bookname) bookcount
from authors a
inner join books b
on a.authorID = b.authorID
where a.authorname = #authorname
group by a.authorid, a.authorname
go
select * from totalbooksbyauthor ('Mark Twain')
I am trying to write a query to get a report that shows which book has been loaned out the most. I have a query to get the actual book loaned out most, but I need to be able to show the title of that book, which is in another table.
SELECT * FROM LOAN;
LOANID BOOKID CUSTID OUTDATE INDATE DUEDATE
SELECT * FROM BOOK;
AUTHORID BOOKID BKISBN BKSTATUS BKTITLE BKSERIES BKTYPE BKNUMBER
The following query is what I have so far and is getting the bookid.:
SELECT Q1.* FROM
(SELECT BOOKID, COUNT(*)
AS BOOK_COUNT
FROM LOAN
GROUP BY LOAN.BOOKID) Q1,
(SELECT MAX(Q2.BOOK_COUNT)
AS HIGH_COUNT
FROM (SELECT BOOKID, COUNT(*)
AS BOOK_COUNT
FROM LOAN
GROUP BY LOAN.BOOKID) Q2) Q3
WHERE Q1.BOOK_COUNT = Q3.HIGH_COUNT;
RESULT:
BOOKID BOOK_COUNT
---------- ----------
387 3
Now I need BkTitle from the Book Table.
Can anyone assist?
Try
select b.bookid, b.BKTITLE , count(l.loanid) as cnt_loan
from book b
inner join loan l on l.bookid = b.bookid
WHERE ROWNUM < 2
group by b.bookid
order by cnt_loan desc