add Selector#where(Function<C, C>)

[k-kagurazaka]

I added Selector#conditionGroup() to build complex condition like:

db.selectFromBook()
        .conditionGroup(it -> it.titleEq("Hoge").or().titleEq("Huga"))
        .and()
        .publisherEq(publisher)
        .toList();

The result SQL is SELECT * FROM Book WHERE (title = "Hoge" OR title = "Huga") AND publisherId = 1.

[gfx]

Looks good, but why not where(C conditionGroup)?

IMO both where(Function<C, C> conditionGroupFunction) and where(C conditiongGroup) are useful.

[gfx]

(memo: I'll release a new version soon after this PR is merged)

[k-kagurazaka]

I agree with you.
I'll try it.

[k-kagurazaka]

I renamed conditionGroup to where and add tests 👍

[gfx]

LGTM