Informix continued...

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

@@ -28,6 +28,7 @@
 import org.hibernate.dialect.NullOrdering;
 import org.hibernate.dialect.Replacer;
 import org.hibernate.dialect.SelectItemReferenceStrategy;
+import org.hibernate.dialect.function.InsertSubstringOverlayEmulation;
 import org.hibernate.engine.jdbc.env.spi.IdentifierCaseStrategy;
 import org.hibernate.engine.jdbc.env.spi.IdentifierHelper;
 import org.hibernate.engine.jdbc.env.spi.IdentifierHelperBuilder;
@@ -105,6 +106,7 @@
 
 import static org.hibernate.exception.spi.TemplatedViolatedConstraintNameExtractor.extractUsingTemplate;
 import static org.hibernate.internal.util.JdbcExceptionHelper.extractErrorCode;
+import static org.hibernate.query.common.TemporalUnit.DAY;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STRING;
 import static org.hibernate.query.sqm.produce.function.StandardFunctionArgumentTypeResolvers.impliedOrInvariant;
 import static org.hibernate.type.SqlTypes.BINARY;
@@ -374,6 +376,9 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 		if ( supportsWindowFunctions() ) {
 			functionFactory.windowFunctions();
 		}
+
+		functionRegistry.register( "overlay",
+				new InsertSubstringOverlayEmulation( typeConfiguration, true ) );
 	}
 
 	@Override
@@ -437,7 +442,7 @@ 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 EPOCH -> "(to_number(cast(cast((?2-datetime(1970-1-1) year to day) as interval day(9) to day) as varchar(12)))*86400+to_number(cast(cast((cast(?2 as datetime hour to second)-datetime(00:00:00) hour to second) as interval second(6) to second) as varchar(9))))";
 			default -> "?1(?2)";
 		};
 	}
@@ -730,15 +735,25 @@ public String timestampdiffPattern(TemporalUnit unit, TemporalType fromTemporalT
 			return "(?3-?2)";
 		}
 		else {
+			if ( fromTemporalType == TemporalType.DATE && toTemporalType == TemporalType.DATE ) {
+				// special case: subtraction of two dates results in an integer number of days
+				return switch ( unit ) {
+					case NATIVE -> "to_number(cast(?3-?2 as lvarchar))*86400";
+					case YEAR, MONTH -> "to_number(cast(cast(extend(?3,year to month)-extend(?2,year to month) as interval ?1(9) to ?1) as varchar(12)))";
+					case DAY -> "to_number(cast(?3-?2 as lvarchar))";
+					case WEEK -> "floor(to_number(cast(?3-?2 as lvarchar))/7)";
+					default -> "to_number(cast(?3-?2 as lvarchar))" + DAY.conversionFactor( unit, this );
+				};
+			}
 			return switch ( unit ) {
 				case NATIVE ->
 					fromTemporalType == TemporalType.TIME
 							// arguably, we don't really need to retain the milliseconds for a time, since times don't usually come with millis
-							? "(mod(to_number(cast(cast(sum(?3-?2) as interval second(6) to second) as varchar(9))),86400)+to_number(cast(cast(sum(?3-?2) as interval fraction to fraction) as varchar(6))))"
-							: "(to_number(cast(cast(sum(?3-?2) as interval day(9) to day) as varchar(12)))*86400+mod(to_number(cast(cast(sum(?3-?2) as interval second(6) to second) as varchar(9))),86400)+to_number(cast(cast(sum(?3-?2) as interval fraction to fraction) as varchar(6))))";
-				case SECOND -> "to_number(cast(cast(sum(?3-?2) as interval second(9) to fraction) as varchar(15)))";
-				case NANOSECOND -> "(to_number(cast(cast(sum(?3-?2) as interval second(9) to fraction) as varchar(15)))*1e9)";
-				default -> "to_number(cast(cast(sum(?3-?2) as interval ?1(9) to ?1) as varchar(12)))";
+							? "(mod(to_number(cast(cast(?3-?2 as interval second(6) to second) as varchar(9))),86400)+to_number(cast(cast(?3-?2 as interval fraction to fraction) as varchar(6))))"
+							: "(to_number(cast(cast(?3-?2 as interval day(9) to day) as varchar(12)))*86400+mod(to_number(cast(cast(?3-?2 as interval second(6) to second) as varchar(9))),86400)+to_number(cast(cast(?3-?2 as interval fraction to fraction) as varchar(6))))";
+				case SECOND -> "to_number(cast(cast(?3-?2 as interval second(9) to fraction) as varchar(15)))";
+				case NANOSECOND -> "(to_number(cast(cast(?3-?2 as interval second(9) to fraction) as varchar(15)))*1e9)";
+				default -> "to_number(cast(cast(?3-?2 as interval ?1(9) to ?1) as varchar(12)))";
 			};
 		}
 	}

hibernate-core/src/main/java/org/hibernate/sql/ast/spi/AbstractSqlAstTranslator.java

@@ -3657,31 +3657,12 @@ public void visitQuerySpec(QuerySpec querySpec) {
 				this.queryPartForRowNumbering = null;
 				this.queryPartForRowNumberingClauseDepth = -1;
 			}
-			String queryGroupAlias = null;
-			if ( currentQueryPart instanceof QueryGroup ) {
-				// We always need query wrapping if we are in a query group and this query spec has a fetch or order by
-				// clause, because of order by precedence in SQL
-				if ( querySpec.hasOffsetOrFetchClause() || querySpec.hasSortSpecifications() ) {
-					queryGroupAlias = "";
-					// If the parent is a query group with a fetch clause we must use a select wrapper,
-					// or if the database does not support simple query grouping, we must use a select wrapper
-					if ( ( !dialect.supportsSimpleQueryGrouping() || currentQueryPart.hasOffsetOrFetchClause() )
-							// We can skip it though if this query spec is being row numbered,
-							// because then we already have a wrapper
-							&& queryPartForRowNumbering != querySpec ) {
-						queryGroupAlias = " grp_" + queryGroupAliasCounter + '_';
-						queryGroupAliasCounter++;
-						appendSql( "select" );
-						appendSql( queryGroupAlias );
-						appendSql( ".* from " );
-						// We need to assign aliases when we render a query spec as subquery to avoid clashing aliases
-						this.needsSelectAliases = this.needsSelectAliases || hasDuplicateSelectItems( querySpec );
-					}
-					else if ( !dialect.supportsDuplicateSelectItemsInQueryGroup() ) {
-						this.needsSelectAliases = this.needsSelectAliases || hasDuplicateSelectItems( querySpec );
-					}
-				}
-			}
+			final String queryGroupAlias =
+					wrapQueryPartsIfNecessary(
+							querySpec,
+							currentQueryPart,
+							queryPartForRowNumbering
+					);
 			queryPartStack.push( querySpec );
 			if ( queryGroupAlias != null ) {
 				appendSql( OPEN_PARENTHESIS );
@@ -3710,6 +3691,40 @@ else if ( !dialect.supportsDuplicateSelectItemsInQueryGroup() ) {
 		}
 	}
 
+	private String wrapQueryPartsIfNecessary(
+			QuerySpec querySpec, QueryPart currentQueryPart, QueryPart queryPartForRowNumbering) {
+		// We always need query wrapping if we are in a query group and if this query
+		// spec has a fetch or order by clause, because of order by precedence in SQL
+		if ( currentQueryPart instanceof QueryGroup
+				&& ( querySpec.hasOffsetOrFetchClause() || querySpec.hasSortSpecifications() ) ) {
+			// If the parent is a query group with a fetch clause, we must use a select wrapper
+			// Or, if the database does not support simple query grouping, we must use a select wrapper
+			if ( ( !dialect.supportsSimpleQueryGrouping() || currentQueryPart.hasOffsetOrFetchClause() )
+					// We can skip it though if this query spec is being row numbered,
+					// because then we already have a wrapper
+					&& queryPartForRowNumbering != querySpec ) {
+				final String queryGroupAlias = " grp_" + queryGroupAliasCounter + '_';
+				queryGroupAliasCounter++;
+				appendSql( "select" );
+				appendSql( queryGroupAlias );
+				appendSql( ".* from " );
+				// We need to assign aliases when we render a query spec as subquery to avoid clashing aliases
+				this.needsSelectAliases = this.needsSelectAliases || hasDuplicateSelectItems( querySpec );
+				return queryGroupAlias;
+			}
+			else if ( !dialect.supportsDuplicateSelectItemsInQueryGroup() ) {
+				this.needsSelectAliases = this.needsSelectAliases || hasDuplicateSelectItems( querySpec );
+				return "";
+			}
+			else {
+				return "";
+			}
+		}
+		else {
+			return null;
+		}
+	}
+
 	protected void visitQueryClauses(QuerySpec querySpec) {
 		visitSelectClause( querySpec.getSelectClause() );
 		visitFromClause( querySpec.getFromClause() );

hibernate-core/src/main/java/org/hibernate/sql/ast/tree/select/SelectStatement.java

@@ -64,24 +64,21 @@ public void accept(SqlAstWalker walker) {
 	}
 
 	@Override
-	public DomainResult createDomainResult(String resultVariable, DomainResultCreationState creationState) {
-		final SelectClause selectClause = queryPart.getFirstQuerySpec().getSelectClause();
-		final TypeConfiguration typeConfiguration = creationState.getSqlAstCreationState()
-				.getCreationContext()
-				.getMappingMetamodel()
-				.getTypeConfiguration();
-		final SqlExpressionResolver sqlExpressionResolver = creationState.getSqlAstCreationState().getSqlExpressionResolver();
-		if ( selectClause.getSqlSelections().size() == 1 ) {
-			final SqlSelection first = selectClause.getSqlSelections().get( 0 );
+	public DomainResult<?> createDomainResult(String resultVariable, DomainResultCreationState creationState) {
+		final List<SqlSelection> sqlSelections =
+				queryPart.getFirstQuerySpec().getSelectClause().getSqlSelections();
+		if ( sqlSelections.size() == 1 ) {
+			final SqlSelection first = sqlSelections.get( 0 );
 			final JdbcMapping jdbcMapping = first.getExpressionType().getSingleJdbcMapping();
-
-			final SqlSelection sqlSelection = sqlExpressionResolver.resolveSqlSelection(
-					this,
-					jdbcMapping.getJdbcJavaType(),
-					null,
-					typeConfiguration
-			);
-
+			final SqlSelection sqlSelection =
+					creationState.getSqlAstCreationState().getSqlExpressionResolver()
+							.resolveSqlSelection(
+									this,
+									jdbcMapping.getJdbcJavaType(),
+									null,
+									creationState.getSqlAstCreationState().getCreationContext()
+											.getTypeConfiguration()
+							);
 			return new BasicResult<>(
 					sqlSelection.getValuesArrayPosition(),
 					resultVariable,
@@ -95,20 +92,22 @@ public DomainResult createDomainResult(String resultVariable, DomainResultCreati
 
 	@Override
 	public void applySqlSelections(DomainResultCreationState creationState) {
-		final SelectClause selectClause = queryPart.getFirstQuerySpec().getSelectClause();
-		final TypeConfiguration typeConfiguration = creationState.getSqlAstCreationState()
-				.getCreationContext()
-				.getMappingMetamodel()
-				.getTypeConfiguration();
-		for ( SqlSelection sqlSelection : selectClause.getSqlSelections() ) {
+		final TypeConfiguration typeConfiguration =
+				creationState.getSqlAstCreationState().getCreationContext()
+						.getTypeConfiguration();
+		final SqlExpressionResolver expressionResolver =
+				creationState.getSqlAstCreationState().getSqlExpressionResolver();
+		for ( SqlSelection sqlSelection :
+				queryPart.getFirstQuerySpec().getSelectClause().getSqlSelections() ) {
 			sqlSelection.getExpressionType().forEachJdbcType(
 					(index, jdbcMapping) -> {
-						creationState.getSqlAstCreationState().getSqlExpressionResolver().resolveSqlSelection(
-								this,
-								jdbcMapping.getJdbcJavaType(),
-								null,
-								typeConfiguration
-						);
+						expressionResolver
+								.resolveSqlSelection(
+										this,
+										jdbcMapping.getJdbcJavaType(),
+										null,
+										typeConfiguration
+								);
 					}
 			);
 		}

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/basic/SubselectTest.java

@@ -15,6 +15,7 @@
 import org.hibernate.annotations.Synchronize;
 import org.hibernate.community.dialect.FirebirdDialect;
 import org.hibernate.community.dialect.DerbyDialect;
+import org.hibernate.community.dialect.InformixDialect;
 import org.hibernate.dialect.SybaseASEDialect;
 
 import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
@@ -39,6 +40,7 @@
 @SkipForDialect(dialectClass = DerbyDialect.class, reason = "Derby doesn't support a CONCAT function")
 @SkipForDialect(dialectClass = SybaseASEDialect.class, reason = "Sybase doesn't support a CONCAT function")
 @SkipForDialect(dialectClass = FirebirdDialect.class, reason = "Firebird doesn't support a CONCAT function")
+@SkipForDialect(dialectClass = InformixDialect.class, reason = "Informix doesn't like CONCAT function in GROUP BY")
 public class SubselectTest {
 
 	@Test

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/GeneratedAnnotationBatchTest.java

@@ -13,6 +13,7 @@
 import org.hibernate.annotations.Generated;
 import org.hibernate.cfg.AvailableSettings;
 
+import org.hibernate.community.dialect.InformixDialect;
 import org.hibernate.testing.orm.junit.DomainModel;
 import org.hibernate.testing.orm.junit.ServiceRegistry;
 import org.hibernate.testing.orm.junit.SessionFactory;
@@ -82,7 +83,7 @@ public void testUpdate(SessionFactoryScope scope) {
 			entities.forEach( ge -> ge.setName( "updated" ) );
 
 			//We need to wait a little to make sure the timestamps produced are different
-			waitALittle();
+			waitALittle( scope );
 			session.flush(); // force update and retrieval of generated values
 
 			entities.forEach( ge -> assertThat( ge.getName() ).isEqualTo( "updated" ) );
@@ -129,9 +130,13 @@ public Instant getUpdateTimestamp() {
 		}
 	}
 
-	private static void waitALittle() {
+	private static void waitALittle(SessionFactoryScope scope) {
+		boolean waitLonger =
+				// informix clock has low resolution on Mac
+				scope.getSessionFactory().getJdbcServices().getDialect()
+						instanceof InformixDialect;
 		try {
-			Thread.sleep( 10 );
+			Thread.sleep( waitLonger ? 1_200 : 10 );
 		}
 		catch (InterruptedException e) {
 			throw new HibernateError( "Unexpected wakeup from test sleep" );

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/GeneratedNoOpUpdateTest.java

@@ -9,8 +9,10 @@
 import java.util.List;
 import java.util.Locale;
 
+import org.hibernate.HibernateError;
 import org.hibernate.annotations.CurrentTimestamp;
 
+import org.hibernate.community.dialect.InformixDialect;
 import org.hibernate.testing.jdbc.SQLStatementInspector;
 import org.hibernate.testing.orm.junit.DomainModel;
 import org.hibernate.testing.orm.junit.Jira;
@@ -77,6 +79,8 @@ public void testUpdate(SessionFactoryScope scope) {
 			assertThat( pizza.getLastUpdated() ).isEqualTo( updatedTime );
 		} );
 
+		waitALittle( scope );
+
 		scope.inTransaction( session -> {
 			final Pizza pizza = session.find( Pizza.class, 1L );
 			assertThat( pizza.getToppings() ).hasSize( 3 )
@@ -177,4 +181,17 @@ public void setPizza(final Pizza pizza) {
 		}
 
 	}
+
+	private static void waitALittle(SessionFactoryScope scope) {
+		boolean waitLonger =
+				// informix clock has low resolution on Mac
+				scope.getSessionFactory().getJdbcServices().getDialect()
+						instanceof InformixDialect;
+		try {
+			Thread.sleep( waitLonger ? 1_200 : 2 );
+		}
+		catch (InterruptedException e) {
+			throw new HibernateError( "Unexpected wakeup from test sleep" );
+		}
+	}
 }

hibernate-core/src/test/java/org/hibernate/orm/test/query/criteria/CriteriaCteOffsetFetchTest.java

@@ -7,6 +7,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.hibernate.community.dialect.InformixDialect;
 import org.hibernate.query.Query;
 import org.hibernate.query.criteria.HibernateCriteriaBuilder;
 import org.hibernate.query.criteria.JpaCriteriaQuery;
@@ -17,6 +18,7 @@
 import org.hibernate.testing.orm.junit.Jira;
 import org.hibernate.testing.orm.junit.SessionFactory;
 import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.hibernate.testing.orm.junit.SkipForDialect;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -38,6 +40,8 @@
 @DomainModel( annotatedClasses = CriteriaCteOffsetFetchTest.Product.class )
 @SessionFactory
 @Jira( "https://hibernate.atlassian.net/browse/HHH-17769" )
+@SkipForDialect(dialectClass = InformixDialect.class,
+		reason = "skip with CTEs seems to be broken")
 public class CriteriaCteOffsetFetchTest {
 	@BeforeAll
 	public void setUp(SessionFactoryScope scope) {
@@ -52,7 +56,7 @@ public void setUp(SessionFactoryScope scope) {
 
 	@AfterAll
 	public void tearDown(SessionFactoryScope scope) {
-		scope.inTransaction( session -> session.createMutationQuery( "delete from Product" ).executeUpdate() );
+		scope.getSessionFactory().getSchemaManager().truncate();
 	}
 
 	@Test