I've got a lookup table for a lookup table and can't work out the SQL to
do a search. Can anyone help?
As an example, consider the following:
Table 1 - books:
fields: book_id, price, title, author
data:
1, 2.99, 'Life', 'A. Slug'
2, 4.99, 'The Universe', 'A. Planet'
Table 2 - book_fields:
fields: field_id, field_name
data:
1, 'cover_colour'
2, 'cover_type'
Table 3 - book_field_look up:
data: book_id, field_id, field_value
1, 1, 'blue'
1, 2, 'hardback'
2, 1, 'blue'
2, 2, 'softback'
How do I do all hardback books that are blue? I'm sure that the answer
is simple, but have a block today :(
--
Rob Allen 4 6410
In message <Mz************ **@rob.mustardh ouse.com>, Rob Allen
<ro***@the-allens.net> writes How do I do all hardback books that are blue? I'm sure that the answer is simple, but have a block today :(
Umm.. That should be "How do I find all the hardback books that are
blue?"
--
Rob Allen
so do you need the sql?
something like
select * from table1, table3 where table1.bood_id = table3.book_id and
table3.field_va lue like "%hardback% ';
"Rob Allen" <ro***@the-allens.net> wrote in message
news:Mz******** ******@rob.must ardhouse.com... I've got a lookup table for a lookup table and can't work out the SQL to do a search. Can anyone help?
As an example, consider the following:
Table 1 - books: fields: book_id, price, title, author data: 1, 2.99, 'Life', 'A. Slug' 2, 4.99, 'The Universe', 'A. Planet'
Table 2 - book_fields: fields: field_id, field_name data: 1, 'cover_colour' 2, 'cover_type'
Table 3 - book_field_look up: data: book_id, field_id, field_value 1, 1, 'blue' 1, 2, 'hardback' 2, 1, 'blue' 2, 2, 'softback'
How do I do all hardback books that are blue? I'm sure that the answer is simple, but have a block today :(
-- Rob Allen
On Mon, 11 Aug 2003 12:35:55 +0000 (UTC), Rob Allen <ro***@the-allens.net>
wrote: I've got a lookup table for a lookup table and can't work out the SQL to do a search. Can anyone help?
As an example, consider the following:
Table 1 - books: fields: book_id, price, title, author data: 1, 2.99, 'Life', 'A. Slug' 2, 4.99, 'The Universe', 'A. Planet'
Table 2 - book_fields: fields: field_id, field_name data: 1, 'cover_colour' 2, 'cover_type'
Table 3 - book_field_look up: data: book_id, field_id, field_value 1, 1, 'blue' 1, 2, 'hardback' 2, 1, 'blue' 2, 2, 'softback'
How do I do all hardback books that are blue? I'm sure that the answer is simple, but have a block today :(
Join to your books table with your field tables twice, once for type, once for
colour, something like:
SELECT b.book_id
FROM books b,
book_fields bf_colour, book_field_look up bfl_colour,
book_fields bf_type, book_field_look up bfl_type
WHERE bf_colour.field _name = 'cover_colour'
AND bf_colour.field _id = bfl_colour.fiel d_id
AND bfl_colour.fiel d_value = 'blue'
AND bfl_colour.book _id = b.book_id
AND bf_type.field_n ame = 'cover_type'
AND bf_type.field_i d = bfl_type.field_ id
AND bfl_type.field_ value = 'hardback'
AND bfl_type.book_i d = b.book_id
--
Andy Hassall (an**@andyh.co. uk) icq(5747695) ( http://www.andyh.co.uk)
Space: disk usage analysis tool ( http://www.andyhsoftware.co.uk/space)
In message <28************ *************** *****@4ax.com>, Andy Hassall
<an**@andyh.co. uk> writes Join to your books table with your field tables twice, once for type, once for colour, something like:
Ah... You can multiply join the same table! So for N search criteria, I
need to join N times...
Thanks !
--
Rob Allen This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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