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Tasiek
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 Posted: Fri Nov 05, 2004 8:55 pm Post subject: Problem with simple SQL query :/ |
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I cant handle simple query :/
I have tables
Books(ISBN, Author, Title) ,
Readers(Pin, Name, LastName)
Borrows(Id , ISBN, Pin)
As you can see in borrows are ISBN borrowed book and pin reader which
borrowed that book.
And now i want choose that books which are not borrowed.
SELECT Books.ISBN, Books.Author, Books.Ttitle FROM Books, Borrows
WHERE Books.ISBN <> Borrows.ISBN
It didnt work, i dont know why
Plz help.
Tasiek
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Andy Flowers
Guest
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| Posted: Fri Nov 05, 2004 9:16 pm Post subject: Re: Problem with simple SQL query :/ |
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Try this one
SELECT Books.isbn, Books.author, Books.title
FROM Books
WHERE Books.isbn NOT IN (select isbn from borrows);
"Tasiek" <tasiekk (AT) tlen (DOT) pl> wrote
| Quote: | I cant handle simple query :/
I have tables
Books(ISBN, Author, Title) ,
Readers(Pin, Name, LastName)
Borrows(Id , ISBN, Pin)
As you can see in borrows are ISBN borrowed book and pin reader which
borrowed that book.
And now i want choose that books which are not borrowed.
SELECT Books.ISBN, Books.Author, Books.Ttitle FROM Books, Borrows
WHERE Books.ISBN <> Borrows.ISBN
It didnt work, i dont know why
Plz help.
Tasiek
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Croaker
Guest
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| Posted: Fri Nov 05, 2004 9:22 pm Post subject: Re: Problem with simple SQL query :/ |
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"Tasiek" <tasiekk (AT) tlen (DOT) pl> wrote
| Quote: | I cant handle simple query :/
I have tables
Books(ISBN, Author, Title) ,
Readers(Pin, Name, LastName)
Borrows(Id , ISBN, Pin)
[...]
SELECT Books.ISBN, Books.Author, Books.Ttitle FROM Books, Borrows
WHERE Books.ISBN <> Borrows.ISBN
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SELECT
Books.ISBN, Books.Author, Books.Ttitle
FROM
Books
WHERE
NOT EXISTS
(
SELECT
Id
FROM
Borrows
WHERE
Borrows.ISDN = Books.ISDN
)
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Tasiek
Guest
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| Posted: Sat Nov 06, 2004 1:46 am Post subject: Re: Problem with simple SQL query :/ |
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and one more .... i dont have subquerias :/
Tasiek
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Christian Kalkhoff
Guest
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| Posted: Sun Nov 07, 2004 12:12 pm Post subject: Re: Problem with simple SQL query :/ |
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Hi Tasiek,
On Fri, 05 Nov 2004 21:55:48 +0100, Tasiek wrote:
| Quote: | I cant handle simple query :/
I have tables
Books(ISBN, Author, Title) ,
Readers(Pin, Name, LastName)
Borrows(Id , ISBN, Pin)
As you can see in borrows are ISBN borrowed book and pin reader which
borrowed that book.
And now i want choose that books which are not borrowed. SELECT
Books.ISBN, Books.Author, Books.Ttitle FROM Books, Borrows WHERE
Books.ISBN <> Borrows.ISBN
As you mentioned you have no subselects i guess you use that mysql thingy. |
:)
I guess you can solve your problem using a JOIN on the tables. See the
statement below, i havent tested it, but it should work (almost).
SELECT B.ISBN, B.Author, B.Title FROM Books B LEFT JOIN Borrows BR ON
B.ISBN = BR.ISBN WHERE BR.ISBN IS NULL
Hope that helps and works. :)
Christian
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