HHH-19934 simplify H2Dialect and move H2V1SequenceSupport to community dialect

Author: MoadElfatihi

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/H2LegacyDialect.java

@@ -31,7 +31,7 @@
 import org.hibernate.dialect.pagination.LimitHandler;
 import org.hibernate.dialect.pagination.LimitOffsetLimitHandler;
 import org.hibernate.dialect.pagination.OffsetFetchLimitHandler;
-import org.hibernate.dialect.sequence.H2V1SequenceSupport;
+import org.hibernate.community.dialect.sequence.H2V1SequenceSupport;
 import org.hibernate.dialect.sequence.H2V2SequenceSupport;
 import org.hibernate.dialect.sequence.SequenceSupport;
 import org.hibernate.dialect.temptable.StandardLocalTemporaryTableStrategy;

hibernate-core/src/main/java/org/hibernate/dialect/sequence/H2V1SequenceSupport.java renamed to hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/sequence/H2V1SequenceSupport.java

@@ -2,9 +2,10 @@
  * SPDX-License-Identifier: Apache-2.0
  * Copyright Red Hat Inc. and Hibernate Authors
  */
-package org.hibernate.dialect.sequence;
+package org.hibernate.community.dialect.sequence;
 
 import org.hibernate.MappingException;
+import org.hibernate.dialect.sequence.SequenceSupport;
 
 /**
  * Sequence support for {@link org.hibernate.dialect.H2Dialect}.

hibernate-core/src/main/java/org/hibernate/dialect/H2Dialect.java

@@ -20,7 +20,6 @@
 import org.hibernate.dialect.lock.spi.LockingSupport;
 import org.hibernate.dialect.pagination.LimitHandler;
 import org.hibernate.dialect.pagination.OffsetFetchLimitHandler;
-import org.hibernate.dialect.sequence.H2V1SequenceSupport;
 import org.hibernate.dialect.sequence.H2V2SequenceSupport;
 import org.hibernate.dialect.sequence.SequenceSupport;
 import org.hibernate.dialect.sql.ast.H2SqlAstTranslator;
@@ -131,10 +130,6 @@
 public class H2Dialect extends Dialect {
 	private static final DatabaseVersion MINIMUM_VERSION = DatabaseVersion.make( 2, 1, 214 );
 
-	private final boolean ansiSequence;
-	private final boolean cascadeConstraints;
-	private final boolean useLocalTime;
-
 	private final SequenceInformationExtractor sequenceInformationExtractor;
 	private final String querySequenceString;
 	private final UniqueDelegate uniqueDelegate = new CreateTableUniqueDelegate(this);
@@ -151,15 +146,6 @@ public H2Dialect() {
 	public H2Dialect(DatabaseVersion version) {
 		super( version );
 
-		// Prior to 1.4.200 there was no support for 'current value for sequence_name'
-		// After 2.0.202 there is no support for 'sequence_name.nextval' and 'sequence_name.currval'
-		ansiSequence = true;
-
-		// Prior to 1.4.200 the 'cascade' in 'drop table' was implicit
-		cascadeConstraints = true;
-		// 1.4.200 introduced changes in current_time and current_timestamp
-		useLocalTime = true;
-
 		sequenceInformationExtractor = SequenceInformationExtractorLegacyImpl.INSTANCE;
 		querySequenceString = "select * from INFORMATION_SCHEMA.SEQUENCES";
 	}
@@ -307,9 +293,9 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 		functionFactory.dayOfWeekMonthYear();
 		functionFactory.weekQuarter();
 		functionFactory.daynameMonthname();
-		if ( useLocalTime ) {
-			functionFactory.localtimeLocaltimestamp();
-		}
+
+		functionFactory.localtimeLocaltimestamp();
+
 		functionFactory.trunc_dateTrunc();
 		functionFactory.dateTrunc();
 		functionFactory.bitLength();
@@ -466,12 +452,12 @@ public int getMaxVarcharLength() {
 
 	@Override
 	public String currentTime() {
-		return useLocalTime ? "localtime" : super.currentTime();
+		return  "localtime";
 	}
 
 	@Override
 	public String currentTimestamp() {
-		return useLocalTime ? "localtimestamp" : super.currentTimestamp();
+		return "localtimestamp";
 	}
 
 	@Override
@@ -713,12 +699,12 @@ public boolean supportsIfExistsAfterTableName() {
 
 	@Override
 	public boolean supportsIfExistsBeforeTableName() {
-		return cascadeConstraints;
+		return true;
 	}
 
 	@Override
 	public boolean supportsIfExistsAfterAlterTable() {
-		return cascadeConstraints;
+		return true;
 	}
 
 	@Override
@@ -728,8 +714,7 @@ public boolean supportsIfExistsBeforeConstraintName() {
 
 	@Override
 	public String getCascadeConstraintsString() {
-		return cascadeConstraints ? " cascade "
-				: super.getCascadeConstraintsString();
+		return " cascade ";
 	}
 
 	@Override
@@ -756,7 +741,7 @@ public boolean dropConstraints() {
 
 	@Override
 	public SequenceSupport getSequenceSupport() {
-		return ansiSequence ? H2V2SequenceSupport.INSTANCE: H2V1SequenceSupport.INSTANCE;
+		return H2V2SequenceSupport.INSTANCE;
 	}
 
 	@Override