HHH-16185 Implement portable date_trunc function emulation and tests

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

@@ -201,6 +201,7 @@ public class HSQLLegacyDialect extends Dialect {
 		functionFactory.rand();
 		functionFactory.trunc();
 //		functionFactory.truncate();
+		functionFactory.dateTrunc_trunc();
 		functionFactory.pi();
 		functionFactory.soundex();
 		functionFactory.reverse();

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

@@ -562,6 +562,7 @@ public class MySQLLegacyDialect extends Dialect {
 		functionFactory.position();
 		functionFactory.nowCurdateCurtime();
 		functionFactory.trunc_truncate();
+		functionFactory.dateTrunc_format( "str_to_date", false );
 		functionFactory.insert();
 		functionFactory.bitandorxornot_operator();
 		functionFactory.bitAndOr();

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

@@ -366,6 +366,10 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
 		}
 		if ( getVersion().isSameOrAfter( 16 ) ) {
 			functionFactory.leastGreatest();
+			functionFactory.dateTrunc_datetrunc();
+		}
+		else {
+			functionFactory.dateTrunc_format( "convert", false );
 		}
 	}
 

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

@@ -218,6 +218,7 @@ public class SybaseLegacyDialect extends AbstractTransactSQLDialect {
 		functionFactory.varPopSamp();
 		functionFactory.trunc_floorPower();
 		functionFactory.round_round();
+		functionFactory.dateTrunc_format( "convert", true );
 
 		// For SQL-Server we need to cast certain arguments to varchar(16384) to be able to concat them
 		functionContributions.getFunctionRegistry().register(

hibernate-core/src/main/java/org/hibernate/dialect/AbstractHANADialect.java

@@ -398,6 +398,7 @@ public abstract class AbstractHANADialect extends Dialect {
 		functionFactory.sinh();
 		functionFactory.tanh();
 		functionFactory.trunc_roundMode();
+		functionFactory.dateTrunc_format( "to_date", false );
 		functionFactory.log10_log();
 		functionFactory.log();
 		functionFactory.bitand();

hibernate-core/src/main/java/org/hibernate/dialect/HSQLDialect.java

@@ -142,6 +142,7 @@ public class HSQLDialect extends Dialect {
 		functionFactory.rand();
 		functionFactory.trunc();
 //		functionFactory.truncate();
+		functionFactory.dateTrunc_trunc();
 		functionFactory.pi();
 		functionFactory.soundex();
 		functionFactory.reverse();

hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java

@@ -561,6 +561,7 @@ public class MySQLDialect extends Dialect {
 		functionFactory.position();
 		functionFactory.nowCurdateCurtime();
 		functionFactory.trunc_truncate();
+		functionFactory.dateTrunc_format( "str_to_date", false );
 		functionFactory.insert();
 		functionFactory.bitandorxornot_operator();
 		functionFactory.bitAndOr();

hibernate-core/src/main/java/org/hibernate/dialect/SQLServerDialect.java

@@ -370,6 +370,10 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
 		}
 		if ( getVersion().isSameOrAfter( 16 ) ) {
 			functionFactory.leastGreatest();
+			functionFactory.dateTrunc_datetrunc();
+		}
+		else {
+			functionFactory.dateTrunc_format( "convert", false );
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/dialect/SpannerDialect.java

@@ -38,6 +38,7 @@ import org.hibernate.persister.entity.Lockable;
 import org.hibernate.query.SemanticException;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
+import org.hibernate.query.sqm.produce.function.StandardFunctionReturnTypeResolvers;
 import org.hibernate.sql.ast.SqlAstTranslator;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
 import org.hibernate.sql.ast.spi.SqlAppender;
@@ -393,7 +394,7 @@ public class SpannerDialect extends Dialect {
 				.setExactArgumentCount( 3 )
 				.register();
 		functionContributions.getFunctionRegistry().namedDescriptorBuilder( "date_trunc" )
-				.setInvariantType( dateType )
+				.setReturnTypeResolver( StandardFunctionReturnTypeResolvers.useArgType( 2 ) )
 				.setExactArgumentCount( 2 )
 				.register();
 		functionContributions.getFunctionRegistry().namedDescriptorBuilder( "date_from_unix_date" )

hibernate-core/src/main/java/org/hibernate/dialect/SybaseDialect.java

@@ -222,6 +222,7 @@ public class SybaseDialect extends AbstractTransactSQLDialect {
 		functionFactory.varPopSamp();
 		functionFactory.trunc_floorPower();
 		functionFactory.round_round();
+		functionFactory.dateTrunc_format( "convert", true );
 
 		// For SQL-Server we need to cast certain arguments to varchar(16384) to be able to concat them
 		functionContributions.getFunctionRegistry().register(

hibernate-core/src/main/java/org/hibernate/dialect/function/CommonFunctionFactory.java

@@ -2560,7 +2560,16 @@ public class CommonFunctionFactory {
 
 	public void dateTrunc() {
 		functionRegistry.patternDescriptorBuilder( "date_trunc", "date_trunc('?1',?2)" )
-				.setInvariantType(timestampType)
+				.setReturnTypeResolver( useArgType( 2 ) )
+				.setExactArgumentCount( 2 )
+				.setParameterTypes( TEMPORAL_UNIT, TEMPORAL )
+				.setArgumentListSignature( "(TEMPORAL_UNIT field, TEMPORAL datetime)" )
+				.register();
+	}
+
+	public void dateTrunc_datetrunc() {
+		functionRegistry.patternDescriptorBuilder( "date_trunc", "datetrunc(?1,?2)" )
+				.setReturnTypeResolver( useArgType( 2 ) )
 				.setExactArgumentCount( 2 )
 				.setParameterTypes( TEMPORAL_UNIT, TEMPORAL )
 				.setArgumentListSignature( "(TEMPORAL_UNIT field, TEMPORAL datetime)" )
@@ -2568,12 +2577,13 @@ public class CommonFunctionFactory {
 	}
 
 	public void dateTrunc_trunc() {
-		functionRegistry.patternDescriptorBuilder( "date_trunc", "trunc(?2,'?1')" )
+		functionRegistry.register( "date_trunc", new DateTruncTrunc( typeConfiguration ) );
-				.setInvariantType(timestampType)
-				.setExactArgumentCount( 2 )
-				.setParameterTypes(TEMPORAL_UNIT, TEMPORAL)
-				.setArgumentListSignature( "(TEMPORAL_UNIT field, TEMPORAL datetime)" )
-				.register();
 	}
 
+	public void dateTrunc_format(String toDateFunction, boolean useConvertToFormat) {
+		functionRegistry.register(
+				"date_trunc",
+				new DateTruncEmulation( toDateFunction, useConvertToFormat, typeConfiguration )
+		);
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/function/DateTruncEmulation.java

@@ -0,0 +1,196 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.dialect.function;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hibernate.query.ReturnableType;
+import org.hibernate.query.spi.QueryEngine;
+import org.hibernate.query.sqm.NodeBuilder;
+import org.hibernate.query.sqm.TemporalUnit;
+import org.hibernate.query.sqm.function.AbstractSqmFunctionDescriptor;
+import org.hibernate.query.sqm.function.FunctionRenderingSupport;
+import org.hibernate.query.sqm.function.SelfRenderingSqmFunction;
+import org.hibernate.query.sqm.produce.function.ArgumentTypesValidator;
+import org.hibernate.query.sqm.produce.function.StandardArgumentsValidators;
+import org.hibernate.query.sqm.produce.function.StandardFunctionArgumentTypeResolvers;
+import org.hibernate.query.sqm.produce.function.StandardFunctionReturnTypeResolvers;
+import org.hibernate.query.sqm.tree.SqmTypedNode;
+import org.hibernate.query.sqm.tree.expression.SqmDurationUnit;
+import org.hibernate.query.sqm.tree.expression.SqmExpression;
+import org.hibernate.query.sqm.tree.expression.SqmFormat;
+import org.hibernate.query.sqm.tree.expression.SqmLiteral;
+import org.hibernate.sql.ast.SqlAstTranslator;
+import org.hibernate.sql.ast.spi.SqlAppender;
+import org.hibernate.sql.ast.tree.SqlAstNode;
+import org.hibernate.type.spi.TypeConfiguration;
+
+import static java.util.Arrays.asList;
+import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TEMPORAL;
+import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TEMPORAL_UNIT;
+
+/**
+ * Emulation of {@code datetrunc} function that leverages
+ * formatting the datetime to string and back to truncate it
+ *
+ * @author Marco Belladelli
+ */
+public class DateTruncEmulation extends AbstractSqmFunctionDescriptor implements FunctionRenderingSupport {
+	private final String toDateFunction;
+
+	private final boolean useConvertToFormat;
+
+	public DateTruncEmulation(String toDateFunction, boolean useConvertToFormat, TypeConfiguration typeConfiguration) {
+		super(
+				"date_trunc",
+				new ArgumentTypesValidator( StandardArgumentsValidators.exactly( 2 ), TEMPORAL_UNIT, TEMPORAL ),
+				StandardFunctionReturnTypeResolvers.useArgType( 2 ),
+				StandardFunctionArgumentTypeResolvers.invariant( typeConfiguration, TEMPORAL_UNIT, TEMPORAL )
+		);
+		this.toDateFunction = toDateFunction;
+		this.useConvertToFormat = useConvertToFormat;
+	}
+
+	@Override
+	public void render(
+			SqlAppender sqlAppender,
+			List<? extends SqlAstNode> sqlAstArguments,
+			SqlAstTranslator<?> walker) {
+		sqlAppender.appendSql( toDateFunction );
+		sqlAppender.append( '(' );
+		if ( !useConvertToFormat ) {
+			if ( toDateFunction.equalsIgnoreCase( "convert" ) ) {
+				sqlAppender.append( "datetime," );
+				sqlAstArguments.get( 0 ).accept( walker );
+			}
+			else {
+				sqlAstArguments.get( 0 ).accept( walker );
+				sqlAppender.append( ',' );
+				sqlAstArguments.get( 1 ).accept( walker );
+			}
+		}
+		else {
+			// custom implementation that uses convert instead of format for Sybase
+			// see: https://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc36271.1600/doc/html/san1393050437990.html
+			sqlAppender.append( "datetime,substring(convert(varchar," );
+			sqlAstArguments.get( 1 ).accept( walker );
+			sqlAppender.append( ",21),1,17-len(" );
+			sqlAstArguments.get( 0 ).accept( walker );
+			sqlAppender.append( "))+" );
+			sqlAstArguments.get( 0  ).accept( walker );
+			sqlAppender.append( ",21" );
+		}
+		sqlAppender.append( ')' );
+	}
+
+	@Override
+	protected <T> SelfRenderingSqmFunction<T> generateSqmFunctionExpression(
+			List<? extends SqmTypedNode<?>> arguments,
+			ReturnableType<T> impliedResultType,
+			QueryEngine queryEngine,
+			TypeConfiguration typeConfiguration) {
+		final NodeBuilder nodeBuilder = queryEngine.getCriteriaBuilder();
+		final TemporalUnit temporalUnit = ( (SqmDurationUnit<?>) arguments.get( 0 ) ).getUnit();
+		final String pattern;
+		final String literal;
+		switch ( temporalUnit ) {
+			case YEAR:
+				pattern = "yyyy";
+				literal = "-01-01 00:00:00";
+				break;
+			case MONTH:
+				pattern = "yyyy-MM";
+				literal = "-01 00:00:00";
+				break;
+			case DAY:
+				pattern = "yyyy-MM-dd";
+				literal = " 00:00:00";
+				break;
+			case HOUR:
+				pattern = "yyyy-MM-dd HH";
+				literal = ":00:00";
+				break;
+			case MINUTE:
+				pattern = "yyyy-MM-dd HH:mm";
+				literal = ":00";
+				break;
+			case SECOND:
+				pattern = "yyyy-MM-dd HH:mm:ss";
+				literal = null;
+				break;
+			default:
+				throw new UnsupportedOperationException( "Temporal unit not supported [" + temporalUnit + "]" );
+		}
+
+		final SqmTypedNode<?> datetime = arguments.get( 1 );
+		final List<SqmTypedNode<?>> args = new ArrayList<>( 2 );
+		if ( !useConvertToFormat ) {
+			// use standard format function
+			final SqmExpression<?> formatExpression = queryEngine.getSqmFunctionRegistry()
+					.findFunctionDescriptor( "format" )
+					.generateSqmExpression(
+							asList(
+									datetime,
+									new SqmFormat(
+											pattern,
+											typeConfiguration.getBasicTypeForJavaType( String.class ),
+											nodeBuilder
+									)
+							),
+							null,
+							queryEngine,
+							typeConfiguration
+					);
+			final SqmExpression<?> formattedDatetime;
+			if ( literal != null ) {
+				formattedDatetime = queryEngine.getSqmFunctionRegistry()
+						.findFunctionDescriptor( "concat" )
+						.generateSqmExpression(
+								asList(
+										formatExpression,
+										new SqmLiteral<>(
+												literal,
+												typeConfiguration.getBasicTypeForJavaType( String.class ),
+												nodeBuilder
+										)
+								),
+								null,
+								queryEngine,
+								typeConfiguration
+						);
+			}
+			else {
+				formattedDatetime = formatExpression;
+			}
+			args.add( formattedDatetime );
+			args.add( new SqmFormat(
+					"yyyy-MM-dd HH:mm:ss",
+					typeConfiguration.getBasicTypeForJavaType( String.class ),
+					nodeBuilder
+			) );
+		}
+		else {
+			args.add( new SqmLiteral<>(
+					literal != null ? literal.replace( "-", "/" ) : "",
+					typeConfiguration.getBasicTypeForJavaType( String.class ),
+					nodeBuilder
+			) );
+			args.add( datetime );
+		}
+		return new SelfRenderingSqmFunction<>(
+				this,
+				this,
+				args,
+				impliedResultType,
+				getArgumentsValidator(),
+				getReturnTypeResolver(),
+				nodeBuilder,
+				"date_trunc"
+		);
+	}
+}

hibernate-core/src/main/java/org/hibernate/dialect/function/DateTruncTrunc.java

@@ -0,0 +1,127 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+package org.hibernate.dialect.function;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hibernate.dialect.OracleDialect;
+import org.hibernate.query.ReturnableType;
+import org.hibernate.query.spi.QueryEngine;
+import org.hibernate.query.sqm.NodeBuilder;
+import org.hibernate.query.sqm.TemporalUnit;
+import org.hibernate.query.sqm.function.AbstractSqmFunctionDescriptor;
+import org.hibernate.query.sqm.function.FunctionRenderingSupport;
+import org.hibernate.query.sqm.function.SelfRenderingSqmFunction;
+import org.hibernate.query.sqm.produce.function.ArgumentTypesValidator;
+import org.hibernate.query.sqm.produce.function.StandardArgumentsValidators;
+import org.hibernate.query.sqm.produce.function.StandardFunctionArgumentTypeResolvers;
+import org.hibernate.query.sqm.produce.function.StandardFunctionReturnTypeResolvers;
+import org.hibernate.query.sqm.tree.SqmTypedNode;
+import org.hibernate.query.sqm.tree.expression.SqmDurationUnit;
+import org.hibernate.query.sqm.tree.expression.SqmLiteral;
+import org.hibernate.sql.ast.SqlAstTranslator;
+import org.hibernate.sql.ast.spi.SqlAppender;
+import org.hibernate.sql.ast.tree.SqlAstNode;
+import org.hibernate.type.spi.TypeConfiguration;
+
+import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TEMPORAL;
+import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TEMPORAL_UNIT;
+
+/**
+ * Trunc function which converts the {@link TemporalUnit}
+ * to the format required for {@code trunc()}
+ *
+ * @author Marco Belladelli
+ */
+public class DateTruncTrunc extends AbstractSqmFunctionDescriptor implements FunctionRenderingSupport {
+
+	public DateTruncTrunc(TypeConfiguration typeConfiguration) {
+		super(
+				"date_trunc",
+				new ArgumentTypesValidator( StandardArgumentsValidators.exactly( 2 ), TEMPORAL_UNIT, TEMPORAL ),
+				StandardFunctionReturnTypeResolvers.useArgType( 2 ),
+				StandardFunctionArgumentTypeResolvers.invariant( typeConfiguration, TEMPORAL_UNIT, TEMPORAL )
+		);
+	}
+
+	@Override
+	public void render(
+			SqlAppender sqlAppender,
+			List<? extends SqlAstNode> sqlAstArguments,
+			SqlAstTranslator<?> walker) {
+		sqlAppender.appendSql( "trunc(" );
+		sqlAstArguments.get( 1 ).accept( walker );
+		sqlAppender.append( ',' );
+		sqlAstArguments.get( 0 ).accept( walker );
+		sqlAppender.append( ')' );
+	}
+
+	@Override
+	protected <T> SelfRenderingSqmFunction<T> generateSqmFunctionExpression(
+			List<? extends SqmTypedNode<?>> arguments,
+			ReturnableType<T> impliedResultType,
+			QueryEngine queryEngine,
+			TypeConfiguration typeConfiguration) {
+		final NodeBuilder nodeBuilder = queryEngine.getCriteriaBuilder();
+		final TemporalUnit temporalUnit = ( (SqmDurationUnit<?>) arguments.get( 0 ) ).getUnit();
+		final String pattern;
+		switch ( temporalUnit ) {
+			case YEAR:
+				pattern = "YYYY";
+				break;
+			case MONTH:
+				pattern = "MM";
+				break;
+			case WEEK:
+				pattern = "IW";
+				break;
+			case DAY:
+				pattern = "DD";
+				break;
+			case HOUR:
+				pattern = "HH";
+				break;
+			case MINUTE:
+				pattern = "MI";
+				break;
+			case SECOND:
+				if ( nodeBuilder.getSessionFactory().getJdbcServices().getDialect() instanceof OracleDialect ) {
+					// Oracle does not support truncating to seconds with the native function, use emulation
+					return new DateTruncEmulation( "to_date", false, typeConfiguration )
+							.generateSqmFunctionExpression(
+									arguments,
+									impliedResultType,
+									queryEngine,
+									typeConfiguration
+							);
+				}
+				pattern = "SS";
+				break;
+			default:
+				throw new UnsupportedOperationException( "Temporal unit not supported [" + temporalUnit + "]" );
+		}
+
+		final List<SqmTypedNode<?>> args = new ArrayList<>( 2 );
+		args.add( new SqmLiteral<>(
+				pattern,
+				typeConfiguration.getBasicTypeForJavaType( String.class ),
+				nodeBuilder
+		) );
+		args.add( arguments.get( 1 ) );
+		return new SelfRenderingSqmFunction<>(
+				this,
+				this,
+				args,
+				impliedResultType,
+				getArgumentsValidator(),
+				getReturnTypeResolver(),
+				nodeBuilder,
+				"date_trunc"
+		);
+	}
+}

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

@@ -513,13 +513,17 @@ public class FunctionTests {
 	}
 
 	@Test
-	@RequiresDialect(H2Dialect.class)
+	@SkipForDialect(dialectClass = DerbyDialect.class, reason = "Derby doesn't support any form of date truncation")
-	@RequiresDialect(DB2Dialect.class)
-	@RequiresDialect(OracleDialect.class)
-	@RequiresDialect(PostgreSQLDialect.class)
 	public void testDateTruncFunction(SessionFactoryScope scope) {
 		scope.inTransaction(
-				session -> session.createQuery("select date_trunc(year,current_timestamp)", Timestamp.class).getSingleResult()
+				session -> {
+					session.createQuery( "select date_trunc(year,current_timestamp)", Timestamp.class ).getSingleResult();
+					session.createQuery( "select date_trunc(month,current_timestamp)", Timestamp.class ).getSingleResult();
+					session.createQuery( "select date_trunc(day,current_timestamp)", Timestamp.class ).getSingleResult();
+					session.createQuery( "select date_trunc(hour,current_timestamp)", Timestamp.class ).getSingleResult();
+					session.createQuery( "select date_trunc(minute,current_timestamp)", Timestamp.class ).getSingleResult();
+					session.createQuery( "select date_trunc(second,current_timestamp)", Timestamp.class ).getSingleResult();
+				}
 		);
 	}