12.4.14. About Relational Comparisons
Comparisons involve one of the comparison operators - =, >, >=, <, <=, <>. HQL also defines != as a comparison operator synonymous with <>. The operands should be of the same type.
Example 12.17. Relational Comparison Examples
// numeric comparison
select c
from Customer c
where c.chiefExecutive.age < 30
// string comparison
select c
from Customer c
where c.name = 'Acme'
// datetime comparison
select c
from Customer c
where c.inceptionDate < {d '2000-01-01'}
// enum comparison
select c
from Customer c
where c.chiefExecutive.gender = com.acme.Gender.MALE
// boolean comparison
select c
from Customer c
where c.sendEmail = true
// entity type comparison
select p
from Payment p
where type(p) = WireTransferPayment
// entity value comparison
select c
from Customer c
where c.chiefExecutive = c.chiefTechnologist
Comparisons can also involve subquery qualifiers -
ALL, ANY, SOME. SOME and ANY are synonymous.
The
ALL qualifier resolves to true if the comparison is true for all of the values in the result of the subquery. It resolves to false if the subquery result is empty.
Example 12.18. ALL Subquery Comparison Qualifier Example
// select all players that scored at least 3 points // in every game. select p from Player p where 3 > all ( select spg.points from StatsPerGame spg where spg.player = p )
The
ANY/SOME qualifier resolves to true if the comparison is true for some of (at least one of) the values in the result of the subquery. It resolves to false if the subquery result is empty.
