Close : Request a null or empty field in the category search.

[meteos77]

I am using the book search tool and I would like BiblioteQ to give me a list of detective story that do not have an isbn13.
(precision : detective story = RP-Roman Policier)

what is the opposite of the % symbol in the search tool

in SQL it would look like this for the % in isbn13 :
SELECT title,author,isbn13 FROM book WHERE location LIKE ('RP-Roman Policier') AND isbn13 IS NOT NULL

but to put in the field ISBN13 : empty or none ?

in SQL it would look like this :
SELECT title,author,isbn13 FROM book WHERE location LIKE ('RP-Roman Crime') AND isbn13 IS NULL

thank you in advance

[textbrowser]

2462279

[textbrowser]

This is both a question and a request.

If you have SQL questions, there are numerous online and physical resources.

https://stackoverflow.com/

BQ is free software, not free customer / technical support. :P

[textbrowser]

I do enjoy the occasional question, occasionally. I also enjoy providing assistance, occasionally.

[meteos77]

what to answer: you are the only one who can assure us of such fast evolutions

again bravo for this generosity and this availability

[textbrowser]

This is a request. Discussions cannot be closed, only deleted.

[textbrowser]

Should be a ticket.

[meteos77]

it's difficult for me to know in advance if the functionality existed with another symbol so in the discussions there is "Q&A" which was the most suitable.

If for your follow-up you want me to create a ticket no worries

[textbrowser]

If it doesn't work as expected, perhaps that's a problem.

[textbrowser]

simplescreenrecorder-2022-11-28_09.59.53.mp4

[textbrowser]

I am using the book search tool and I would like BiblioteQ to give me a list of detective story that do not have an isbn13. (precision : detective story = RP-Roman Policier)

what is the opposite of the % symbol in the search tool

in SQL it would look like this for the % in isbn13 : SELECT title,author,isbn13 FROM book WHERE location LIKE ('RP-Roman Policier') AND isbn13 IS NOT NULL

but to put in the field ISBN13 : empty or none ?

in SQL it would look like this : SELECT title,author,isbn13 FROM book WHERE location LIKE ('RP-Roman Crime') AND isbn13 IS NULL

thank you in advance

The opposite of the wildcard? A non-wildcard. There are restrictions with null values. For example, LIKE '%' on a null value is nonsensical.

[textbrowser]

This is a reason for the existence of IS NULL.

[textbrowser]

Not a simple discussion.

https://www.sqlite.org/nulls.html

[meteos77]

I'm not there yet with SQL but it's good to know for future queries thanks for the link

[textbrowser]

https://www.sqlite.org/lang_corefunc.html#coalesce

[textbrowser]

The recent change will address null ISBNs and non-null ISBNs. For null ISBNs, it's expected that both ISBN-10 and ISBN-13 are null because and / or operators. If you have an ISBN, it can be converted into another form so you shouldn't have one but not the other. If you do, that's a fault on the administrator. I don't have a trigger to enforce that both are present if one is. Anyway.

[meteos77]

In our main database we have no isbn-10. Do you advise to fill in isbn10 if isbn13 present?

[meteos77]

currently my tests
search with ISBN-13 left as is (so displays ISBN-13)
result: NULLS

search with ISBN-13 with %
result: NULLs and FILLED

search with ISBN-13 with 9%
result: the FILLED