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7.5. Aggregate functions

HQL queries may even return the results of aggregate functions on properties:
select avg(cat.weight), sum(cat.weight), max(cat.weight), count(cat)
from Cat cat
The supported aggregate functions are
  • avg(...), avg(distinct ...), sum(...), sum(distinct ...), min(...), max(...)
  • count(*)
  • count(...), count(distinct ...), count(all...)
You may use arithmetic operators, concatenation, and recognized SQL functions in the select clause (depending on configured dialect, HQL specific feature):
select cat.weight + sum(kitten.weight) 
from Cat cat 
    join cat.kittens kitten
group by, cat.weight
select firstName||' '||initial||' '||upper(lastName) from Person
The distinct and all keywords may be used and have the same semantics as in SQL.
select distinct from Cat cat

select count(distinct, count(cat) from Cat cat