Question

imagine I have two entities – Tag and Text where Text has multiple tags and there are several things I would like to do with them. I would be very happy if you can help me come up with an elegant solution.

I want to search for Text entities by multiple Tags at once – all tags must match

I want to search for Text entities by multiple Tags, second parameter specifies how many must mach

I would like to specify pairs or triplets of tags where at least one of every pair must match

Any suggestions? Thank you

Answer 1

The answers to these are pretty much the same, whether you use SQL, HQL or JPQL:

I want to search for Text entities by
multiple Tags at once – all tags must
match

where text like %tag1% and text like %tag2% // etc.

I want to search for Text entities by
multiple Tags, second parameter
specifies how many must mach

StringBuilder sb = new StringBuilder();
for(int i = 0; i < howmany; i++){
   sb.append('%').append(param);
}
sb.append('%');

String query = "some query text where " + sb.toString()

I would like to specify pairs or
triplets of tags where at least one of
every pair must match

where text like %tag1% or text like %tag2% -- etc