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change the new syntax for HQL collection-aggregates 

this feels more consistent to me, and avoids introducing "new" syntax
This commit is contained in:
Gavin King 2022-02-08 15:49:43 +01:00
parent 5828536428
commit 9ebac67737
4 changed files with 145 additions and 68 deletions
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67
documentation/src/main/asciidoc/userguide/chapters/query/hql/QueryLanguage.adoc
View File

@ -970,6 +970,8 @@ The following functions may be applied to a collection-valued path expression to
| Only legal as a terminal path, and only allowed in the `select` clause. | Only legal as a terminal path, and only allowed in the `select` clause.
|=== |===
We've intentionally left two functions off this list, so we can come back to them <<hql-elements-indices,later>>.
NOTE: Of these, only `index()` is defined by the JPQL specification. NOTE: Of these, only `index()` is defined by the JPQL specification.
[[hql-collection-qualification-example]] [[hql-collection-qualification-example]]
@ -994,37 +996,6 @@ include::{sourcedir}/HQLTest.java[tags=hql-collection-index-operator-example]
---- ----
==== ====
There are even more functions which accept a collection-valued attribute or to-many association:
|===
| HQL Function | Synonym | Old syntax | Applies to | Purpose
| `max(element&nbsp;x)` | `max(value&nbsp;x)` | `maxelement(x)` | Any collection with sortable elements | The maximum element or map value
| `min(element&nbsp;x)` | `min(value&nbsp;x)` | `minelement(x)` | Any collection with sortable elements | The minimum element or map value
| `sum(element&nbsp;x)` | `sum(value&nbsp;x)` | &mdash; | Any collection with numeric elements | The sum of the elements or map values
| `avg(element&nbsp;x)` | `avg(value&nbsp;x)` | &mdash; | Any collection with numeric elements | The sum of the elements or map values
| `max(index&nbsp;x)` | `max(key&nbsp;x)` | `maxindex(x)` | Indexed collections (lists and maps) | The maximum list index or map key
| `min(index&nbsp;x)` | `min(key&nbsp;x)` | `minindex(x)` | Indexed collections (lists and maps) | The minimum list index or map key
| `sum(index&nbsp;x)` | `sum(key&nbsp;x)` | &mdash; | Indexed collections (lists and maps) | The sum of the list indexes or map keys
| `avg(index&nbsp;x)` | `avg(key&nbsp;x)`| &mdash; | Indexed collections (lists and maps) | The average of the list indexes or map keys
|===
We've intentionally left two functions off this list, so we can come back to them <<hql-elements-indices,later>>.
[[hql-collection-expressions-example]]
//.Collection-related expressions examples
====
[source, JAVA, indent=0]
----
include::{sourcedir}/HQLTest.java[tags=hql-collection-expressions-example]
----
====
[TIP]
====
These operations can almost always be written in another way, without the use of these convenience functions.
====
[[hql-more-functions]] [[hql-more-functions]]
==== More HQL functions ==== More HQL functions
@ -1223,7 +1194,7 @@ As you can guess, `not like` and `not ilike` are the enemies of `like` and `ilik
[[hql-elements-indices]] [[hql-elements-indices]]
==== Elements and indices ==== Elements and indices
There's two special HQL functions that we didn't mention <<hql-more-functions,earlier>>, since they're only useful in conjunction with the predicate operators we're about to meet. There's two special HQL functions that we didn't mention <<hql-collection-qualification,earlier>>, since they're only useful in conjunction with the predicate operators we're about to meet.
These functions are only allowed in the `where` clause, and result in a subquery in the generated SQL. These functions are only allowed in the `where` clause, and result in a subquery in the generated SQL.
Indeed, you can think of them as just a shortcut way to write a subquery. Indeed, you can think of them as just a shortcut way to write a subquery.
@ -1896,6 +1867,38 @@ HQL defines the two additional aggregate functions which accept a logical predic
NOTE: Aggregate functions usually appear in the `select` clause, but control over aggregation is the responsibility of the `group by` clause, as described <<hql-group-by,below>>. NOTE: Aggregate functions usually appear in the `select` clause, but control over aggregation is the responsibility of the `group by` clause, as described <<hql-group-by,below>>.
[[hql-aggregate-functions-collections]]
==== Aggregate functions and collections
The `elements()` and `indices()` functions we met <<hql-elements-indices,earlier>> let us apply aggregate functions to a collection:
|===
| New syntax | Legacy HQL function | Applies to | Purpose
| `max(elements(x))` | `maxelement(x)` | Any collection with sortable elements | The maximum element or map value
| `min(elements(x))` | `minelement(x)` | Any collection with sortable elements | The minimum element or map value
| `sum(elements(x))` | &mdash; | Any collection with numeric elements | The sum of the elements or map values
| `avg(elements(x))` | &mdash; | Any collection with numeric elements | The average of the elements or map values
| `max(indices(x))` | `maxindex(x)` | Indexed collections (lists and maps) | The maximum list index or map key
| `min(indices(x))` | `minindex(x)` | Indexed collections (lists and maps) | The minimum list index or map key
| `sum(indices(x))` | &mdash; | Indexed collections (lists and maps) | The sum of the list indexes or map keys
| `avg(indices(x))` | &mdash; | Indexed collections (lists and maps) | The average of the list indexes or map keys
|===
[[hql-collection-expressions-example]]
//.Collection-related expressions examples
====
[source, JAVA, indent=0]
----
include::{sourcedir}/HQLTest.java[tags=hql-collection-expressions-example]
----
====
[TIP]
====
These operations can almost always be written in another way, without the use of these convenience functions.
====
[[hql-aggregate-functions-filter]] [[hql-aggregate-functions-filter]]
==== `filter` ==== `filter`

9
documentation/src/test/java/org/hibernate/userguide/hql/HQLTest.java
View File

@ -35,7 +35,6 @@ import org.hibernate.dialect.SybaseASEDialect;
import org.hibernate.dialect.TiDBDialect; import org.hibernate.dialect.TiDBDialect;
import org.hibernate.orm.test.jpa.BaseEntityManagerFunctionalTestCase; import org.hibernate.orm.test.jpa.BaseEntityManagerFunctionalTestCase;
import org.hibernate.query.QueryProducer; import org.hibernate.query.QueryProducer;
import org.hibernate.testing.Skip;
import org.hibernate.type.StandardBasicTypes; import org.hibernate.type.StandardBasicTypes;
import org.hibernate.userguide.model.Account; import org.hibernate.userguide.model.Account;
import org.hibernate.userguide.model.AddressType; import org.hibernate.userguide.model.AddressType;
@ -1801,7 +1800,7 @@ public class HQLTest extends BaseEntityManagerFunctionalTestCase {
List<Phone> phones = entityManager.createQuery( List<Phone> phones = entityManager.createQuery(
"select p " + "select p " +
"from Phone p " + "from Phone p " +
"where max(element p.calls) = :call", "where max(elements(p.calls)) = :call",
Phone.class) Phone.class)
.setParameter("call", call) .setParameter("call", call)
.getResultList(); .getResultList();
@ -1819,7 +1818,7 @@ public class HQLTest extends BaseEntityManagerFunctionalTestCase {
List<Phone> phones = entityManager.createQuery( List<Phone> phones = entityManager.createQuery(
"select p " + "select p " +
"from Phone p " + "from Phone p " +
"where min(element p.calls) = :call", "where min(elements(p.calls)) = :call",
Phone.class) Phone.class)
.setParameter("call", call) .setParameter("call", call)
.getResultList(); .getResultList();
@ -1836,7 +1835,7 @@ public class HQLTest extends BaseEntityManagerFunctionalTestCase {
List<Person> persons = entityManager.createQuery( List<Person> persons = entityManager.createQuery(
"select p " + "select p " +
"from Person p " + "from Person p " +
"where max(index p.phones) = 0", "where max(indices(p.phones)) = 0",
Person.class) Person.class)
.getResultList(); .getResultList();
//end::hql-collection-expressions-example[] //end::hql-collection-expressions-example[]
@ -1993,7 +1992,7 @@ public class HQLTest extends BaseEntityManagerFunctionalTestCase {
List<Person> persons = entityManager.createQuery( List<Person> persons = entityManager.createQuery(
"select pr " + "select pr " +
"from Person pr " + "from Person pr " +
"where pr.phones[max(index pr.phones)].type = 'LAND_LINE'", "where pr.phones[max(indices(pr.phones))].type = 'LAND_LINE'",
Person.class) Person.class)
.getResultList(); .getResultList();
//end::hql-collection-index-operator-example[] //end::hql-collection-index-operator-example[]

16
hibernate-core/src/main/antlr/org/hibernate/grammars/hql/HqlParser.g4
View File

@ -1008,10 +1008,10 @@ jpaCollectionFunction
indexAggregateFunction indexAggregateFunction
: MAXINDEX LEFT_PAREN path RIGHT_PAREN : MAXINDEX LEFT_PAREN path RIGHT_PAREN
| MININDEX LEFT_PAREN path RIGHT_PAREN | MININDEX LEFT_PAREN path RIGHT_PAREN
| MAX LEFT_PAREN (INDEX|KEY) path RIGHT_PAREN | MAX LEFT_PAREN INDICES LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| MIN LEFT_PAREN (INDEX|KEY) path RIGHT_PAREN | MIN LEFT_PAREN INDICES LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| SUM LEFT_PAREN (INDEX|KEY) path RIGHT_PAREN | SUM LEFT_PAREN INDICES LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| AVG LEFT_PAREN (INDEX|KEY) path RIGHT_PAREN | AVG LEFT_PAREN INDICES LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
; ;
/** /**
@ -1020,10 +1020,10 @@ indexAggregateFunction
elementAggregateFunction elementAggregateFunction
: MAXELEMENT LEFT_PAREN path RIGHT_PAREN : MAXELEMENT LEFT_PAREN path RIGHT_PAREN
| MINELEMENT LEFT_PAREN path RIGHT_PAREN | MINELEMENT LEFT_PAREN path RIGHT_PAREN
| MAX LEFT_PAREN (ELEMENT|VALUE) path RIGHT_PAREN | MAX LEFT_PAREN ELEMENTS LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| MIN LEFT_PAREN (ELEMENT|VALUE) path RIGHT_PAREN | MIN LEFT_PAREN ELEMENTS LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| SUM LEFT_PAREN (ELEMENT|VALUE) path RIGHT_PAREN | SUM LEFT_PAREN ELEMENTS LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
| AVG LEFT_PAREN (ELEMENT|VALUE) path RIGHT_PAREN | AVG LEFT_PAREN ELEMENTS LEFT_PAREN path RIGHT_PAREN RIGHT_PAREN
; ;
/** /**

115
hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java
View File

@ -89,39 +89,115 @@ public class FunctionTests {
} }
); );
} }
//
// @Test
// public void testMaxMinSumIndexElement(SessionFactoryScope scope) {
// scope.inTransaction(
// session -> {
// assertThat( session.createQuery("select max(index eol.listOfNumbers) from EntityOfLists eol")
// .getSingleResult(), is(1) );
// assertThat( session.createQuery("select max(element eol.listOfNumbers) from EntityOfLists eol")
// .getSingleResult(), is(2.0) );
//
// assertThat( session.createQuery("select sum(index eol.listOfNumbers) from EntityOfLists eol")
// .getSingleResult(), is(1) );
// assertThat( session.createQuery("select sum(element eol.listOfNumbers) from EntityOfLists eol")
// .getSingleResult(), is(3.0) );
//
// //TODO: why does this fail??
//// assertThat( session.createQuery("select avg(index eol.listOfNumbers) from EntityOfLists eol")
//// .getSingleResult(), is(0.5) );
// assertThat( session.createQuery("select avg(element eol.listOfNumbers) from EntityOfLists eol")
// .getSingleResult(), is(1.5) );
//
// assertThat( session.createQuery("select max(index eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1) );
// assertThat( session.createQuery("select max(element eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1.0) );
//
// assertThat( session.createQuery("select sum(index eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1) );
// assertThat( session.createQuery("select sum(element eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1.0) );
//
// assertThat( session.createQuery("select avg(index eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1) );
// assertThat( session.createQuery("select avg(element eom.numberByNumber) from EntityOfMaps eom")
// .getSingleResult(), is(1.0) );
// }
// );
// }
//
@Test @Test
public void testMaxMinSumIndexElement(SessionFactoryScope scope) { public void testAltMaxMinSumIndexElement(SessionFactoryScope scope) {
//TODO: make the commented tests work!
scope.inTransaction( scope.inTransaction(
session -> { session -> {
assertThat( session.createQuery("select max(index eol.listOfNumbers) from EntityOfLists eol") // assertThat( session.createQuery("select max(index(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(1) ); // .getSingleResult(), is(1) );
assertThat( session.createQuery("select max(element eol.listOfNumbers) from EntityOfLists eol") assertThat( session.createQuery("select max(element(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(2.0) ); .getSingleResult(), is(2.0) );
assertThat( session.createQuery("select sum(index eol.listOfNumbers) from EntityOfLists eol") // assertThat( session.createQuery("select sum(index(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(1L) ); // .getSingleResult(), is(1) );
assertThat( session.createQuery("select sum(element eol.listOfNumbers) from EntityOfLists eol") assertThat( session.createQuery("select sum(element(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(3.0) ); .getSingleResult(), is(3.0) );
assertThat( session.createQuery("select avg(index eol.listOfNumbers) from EntityOfLists eol") // assertThat( session.createQuery("select avg(index(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(0.5) ); // .getSingleResult(), is(0.5) );
assertThat( session.createQuery("select avg(element eol.listOfNumbers) from EntityOfLists eol") assertThat( session.createQuery("select avg(element(eol.listOfNumbers)) from EntityOfLists eol group by eol")
.getSingleResult(), is(1.5) ); .getSingleResult(), is(1.5) );
assertThat( session.createQuery("select max(index eom.numberByNumber) from EntityOfMaps eom") // assertThat( session.createQuery("select max(index(eom.numberByNumber)) from EntityOfMaps eom group by eom")
// .getSingleResult(), is(1) );
assertThat( session.createQuery("select max(element(eom.numberByNumber)) from EntityOfMaps eom group by eom")
.getSingleResult(), is(1.0) );
// assertThat( session.createQuery("select sum(index(eom.numberByNumber)) from EntityOfMaps eom group by eom")
// .getSingleResult(), is(1) );
assertThat( session.createQuery("select sum(element(eom.numberByNumber)) from EntityOfMaps eom group by eom")
.getSingleResult(), is(1.0) );
// assertThat( session.createQuery("select avg(index(eom.numberByNumber)) from EntityOfMaps eom group by eom")
// .getSingleResult(), is(1) );
assertThat( session.createQuery("select avg(element(eom.numberByNumber)) from EntityOfMaps eom group by eom")
.getSingleResult(), is(1.0) );
}
);
}
@Test
public void testMaxMinSumIndicesElements(SessionFactoryScope scope) {
scope.inTransaction(
session -> {
assertThat( session.createQuery("select max(indices(eol.listOfNumbers)) from EntityOfLists eol")
.getSingleResult(), is(1) ); .getSingleResult(), is(1) );
assertThat( session.createQuery("select max(element eom.numberByNumber) from EntityOfMaps eom") assertThat( session.createQuery("select max(elements(eol.listOfNumbers)) from EntityOfLists eol")
.getSingleResult(), is(2.0) );
assertThat( session.createQuery("select sum(indices(eol.listOfNumbers)) from EntityOfLists eol")
.getSingleResult(), is(1) ); //TODO: should be Long
assertThat( session.createQuery("select sum(elements(eol.listOfNumbers)) from EntityOfLists eol")
.getSingleResult(), is(3.0) );
// assertThat( session.createQuery("select avg(indices(eol.listOfNumbers)) from EntityOfLists eol")
// .getSingleResult(), is(0.5) ); //TODO: FIX!!
assertThat( session.createQuery("select avg(elements(eol.listOfNumbers)) from EntityOfLists eol")
.getSingleResult(), is(1.5) );
assertThat( session.createQuery("select max(indices(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1) );
assertThat( session.createQuery("select max(elements(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1.0) ); .getSingleResult(), is(1.0) );
assertThat( session.createQuery("select sum(index eom.numberByNumber) from EntityOfMaps eom") assertThat( session.createQuery("select sum(indices(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1L) ); .getSingleResult(), is(1) ); //TODO: should be Long
assertThat( session.createQuery("select sum(element eom.numberByNumber) from EntityOfMaps eom") assertThat( session.createQuery("select sum(elements(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1.0) ); .getSingleResult(), is(1.0) );
assertThat( session.createQuery("select avg(index eom.numberByNumber) from EntityOfMaps eom") assertThat( session.createQuery("select avg(indices(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1.0) ); .getSingleResult(), is(1) ); //TODO: should be Double
assertThat( session.createQuery("select avg(element eom.numberByNumber) from EntityOfMaps eom") assertThat( session.createQuery("select avg(elements(eom.numberByNumber)) from EntityOfMaps eom")
.getSingleResult(), is(1.0) ); .getSingleResult(), is(1.0) );
} }
); );
@ -141,7 +217,6 @@ public class FunctionTests {
assertThat( session.createQuery("select sum(element(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol") assertThat( session.createQuery("select sum(element(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol")
.getSingleResult(), is(3.0) ); .getSingleResult(), is(3.0) );
//TODO: why does this fail??
assertThat( session.createQuery("select avg(index(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol") assertThat( session.createQuery("select avg(index(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol")
.getSingleResult(), is(0.5) ); .getSingleResult(), is(0.5) );
assertThat( session.createQuery("select avg(element(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol") assertThat( session.createQuery("select avg(element(l)) from EntityOfLists eol join eol.listOfNumbers l group by eol")