Support unlimited And expressions in GORM domain class finders, eg, Book.findByAuthorAndTitleAndPublished(a, t, true)

I have the same issue here, and it took me some time to find this limitation (it is described), but it would be nice if somethine like this would be possible:

Event.findEventByNameAndStartDateAndLocation....

Now I get a strange error message :

org.codehaus.groovy.grails.exceptions.InvalidPropertyException: No property found for name [startDateAndTitle] for class [class Event]

Personally, I'd flag as "bad practice" the fact of using more than two expressions in dynamic finders.
It's not even readable anymore if the method name is too long.

We've decided not to fix this as it is impossible to disambiguate between something like:

Book.findByTitleOrAuthorOrGenreAndReleaseDate(..)

How do you know whether "(title or author or genre) and release date" or "(title or author) or (genre and release date)"?

Graeme,

Grails don't need to worry about this disambiguation, users need. I personally think that this issue must be fixed in order to avoid surprises and keep things working. Users, on the other side, should care about write clean/readable code and avoid expressions like that.

Kind Regards

+1

The original issue doesn't mention "Or"s in the method name.

Just support many "And"s.

It's something many new users will try assuming it works and trip up on.

Why not reopen this one?

Note that if this is implemented, the unit test support will also have to be updated.

won't have time for this

I think there are a couple of different pieces here. One is to support multiple AND or multiple OR (those are basically the same thing from a solution perspective). The other is to support mixing AND and OR, which may be more complicated.

The mixing could also be possible by using different keywords such as "InclAnd" or something like that which would be emulating <someexpr>(Prev and Present). If the prev one is also using a "InclAnd" the generated expression should be <someexpr>(PrevPrev and Prev and Present)

Ravi,

If many folks are in favor of something like that we would consider it. My personal opinion is that we probably should not complicate the expressions which can be represented in the method name like this. A big part of the value of dynamic finders is you get a concise, expressive, easy to read and easy to write method name which clearly represents the query. If the expression gets very complicated at all, I think that query is better expressed as a criteria query.

I think the thing to do is support unlimited AND, or unlimited OR but not allow mixing them in a dynamic finder name.

I welcome input.

Just out of curiosity is this documented?

Ravi,

Yes, it is. The latest user guide includes the following text:

You can combine as many criteria as you like, but they must all be combined with And or all Or. If you need to combine And and Or or if the number of criteria creates a very long method name, just convert the query to a Criteria or HQL query.

See http://hudson.grails.org/job/grails_docs_2.0.x/lastSuccessfulBuild/artifact/build/docs/guide/GORM.html#finders