get 'extract(epoch)' working Informix

yay!

Author: gavinking

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/InformixDialect.java

@@ -435,6 +435,7 @@ public String extractPattern(TemporalUnit unit) {
 			case HOUR -> "to_number(to_char(?2,'%H'))";
 			case DAY_OF_WEEK -> "(weekday(?2)+1)";
 			case DAY_OF_MONTH -> "day(?2)";
+			case EPOCH -> "(to_number(cast(cast(sum(?2-datetime(1970-1-1) year to day) as interval day(9) to day) as varchar(12)))*86400+to_number(cast(cast(sum(cast(?2 as datetime hour to second)-datetime(00:00:00) hour to second) as interval second(6) to second) as varchar(9))))";
 			case NATIVE -> "((to_number(cast(cast(sum(?2) as interval day(9) to day) as varchar(12)))*86400+mod(to_number(cast(cast(sum(?2) as interval second(6) to second) as varchar(9))),86400)+to_number(cast(cast(sum(?2) as interval fraction to fraction) as varchar(6))))*1e3)";
 			default -> "?1(?2)";
 		};

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

@@ -72,8 +72,10 @@
 
 import static org.hamcrest.CoreMatchers.*;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 import static org.hamcrest.Matchers.isOneOf;
 
+import static org.hamcrest.Matchers.lessThanOrEqualTo;
 import static org.hibernate.testing.orm.domain.gambit.EntityOfBasics.Gender.FEMALE;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -2141,13 +2143,18 @@ public void testExtractFunctionDayOfWeekOf(SessionFactoryScope scope) {
 	}
 
 	@Test
-	@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsExtractEpoch.class)
 	public void testExtractFunctionEpoch(SessionFactoryScope scope) {
 		scope.inTransaction(
 				session -> {
-					session.createQuery("select extract(epoch from local datetime)", Long.class).getSingleResult();
+					long before = Instant.now().getEpochSecond()-1;
+					long epoch = session.createQuery( "select extract(epoch from local datetime)", Long.class ).getSingleResult();
+					long after = Instant.now().getEpochSecond()+1;
+					assertThat( epoch, allOf( greaterThanOrEqualTo( before ), lessThanOrEqualTo( after ) ) );
+
 					session.createQuery("select extract(epoch from offset datetime)", Long.class).getSingleResult();
-					assertThat( session.createQuery("select extract(epoch from datetime 1974-03-23 12:35)", Long.class).getSingleResult(), is(133274100L) );
+
+					assertThat( session.createQuery("select extract(epoch from datetime 1974-03-23 12:35)", Long.class).getSingleResult(),
+							is(133274100L) );
 				}
 		);
 	}
@@ -2692,7 +2699,6 @@ public void testHexFunction(SessionFactoryScope scope) {
 
 	@Test
 	@JiraKey("HHH-18837")
-	@RequiresDialectFeature(feature = DialectFeatureChecks.SupportsExtractEpoch.class)
 	public void testEpochFunction(SessionFactoryScope scope) {
 
 		LocalDate someLocalDate = LocalDate.of( 2013, 7, 5 );

hibernate-testing/src/main/java/org/hibernate/testing/orm/junit/DialectFeatureChecks.java

@@ -557,13 +557,6 @@ public boolean apply(Dialect dialect) {
 		}
 	}
 
-	public static class SupportsExtractEpoch implements DialectFeatureCheck {
-		public boolean apply(Dialect dialect) {
-			// I could not find any reasonable way to implement this on Informix
-			return !( dialect instanceof InformixDialect );
-		}
-	}
-
 	public static class SupportsExtractDayOfWeekYearMonth implements DialectFeatureCheck {
 		public boolean apply(Dialect dialect) {
 			return !( dialect instanceof InformixDialect );