HHH-14624 Oracle from version 12 started supporting the syntax for pagination

hibernate-core/src/main/java/org/hibernate/dialect/Oracle12cDialect.java

@@ -10,6 +10,9 @@ import org.hibernate.boot.model.TypeContributions;
 import org.hibernate.cfg.Environment;
 import org.hibernate.dialect.identity.IdentityColumnSupport;
 import org.hibernate.dialect.identity.Oracle12cIdentityColumnSupport;
+import org.hibernate.dialect.pagination.AbstractLimitHandler;
+import org.hibernate.dialect.pagination.LimitHandler;
+import org.hibernate.dialect.pagination.Oracle12LimitHandler;
 import org.hibernate.engine.config.spi.ConfigurationService;
 import org.hibernate.engine.config.spi.StandardConverters;
 import org.hibernate.service.ServiceRegistry;
@@ -24,6 +27,8 @@ import org.hibernate.type.WrappedMaterializedBlobType;
 public class Oracle12cDialect extends Oracle10gDialect {
 	public static final String PREFER_LONG_RAW = "hibernate.dialect.oracle.prefer_long_raw";
 
+	private static final AbstractLimitHandler LIMIT_HANDLER = Oracle12LimitHandler.INSTANCE;
+
 	public Oracle12cDialect() {
 		super();
 		getDefaultProperties().setProperty( Environment.BATCH_VERSIONED_DATA, "true" );
@@ -62,4 +67,9 @@ public class Oracle12cDialect extends Oracle10gDialect {
 	public IdentityColumnSupport getIdentityColumnSupport() {
 		return new Oracle12cIdentityColumnSupport();
 	}
+
+	@Override
+	public LimitHandler getLimitHandler() {
+		return LIMIT_HANDLER;
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/pagination/LimitHandler.java

@@ -9,6 +9,7 @@ package org.hibernate.dialect.pagination;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
+import org.hibernate.engine.spi.QueryParameters;
 import org.hibernate.engine.spi.RowSelection;
 
 /**
@@ -44,6 +45,18 @@ public interface LimitHandler {
 	 */
 	String processSql(String sql, RowSelection selection);
 
+	/**
+	 * Return processed SQL query.
+	 *
+	 * @param sql the SQL query to process.
+	 * @param queryParameters the queryParameters.
+	 *
+	 * @return Query statement with LIMIT clause applied.
+	 */
+	default String processSql(String sql, QueryParameters queryParameters ){
+		return processSql( sql, queryParameters.getRowSelection() );
+	}
+
 	/**
 	 * Bind parameter values needed by the LIMIT clause before original SELECT statement.
 	 *

hibernate-core/src/main/java/org/hibernate/dialect/pagination/Oracle12LimitHandler.java

@@ -0,0 +1,181 @@
+/*
+ * 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.pagination;
+
+import java.util.Locale;
+
+import org.hibernate.LockMode;
+import org.hibernate.LockOptions;
+import org.hibernate.engine.spi.QueryParameters;
+import org.hibernate.engine.spi.RowSelection;
+
+/**
+ * A {@link LimitHandler} for databases which support the
+ * ANSI SQL standard syntax {@code FETCH FIRST m ROWS ONLY}
+ * and {@code OFFSET n ROWS FETCH NEXT m ROWS ONLY}.
+ *
+ * @author Gavin King
+ */
+public class Oracle12LimitHandler extends AbstractLimitHandler {
+
+	public boolean bindLimitParametersInReverseOrder;
+	public boolean useMaxForLimit;
+
+	public static final Oracle12LimitHandler INSTANCE = new Oracle12LimitHandler();
+
+	Oracle12LimitHandler() {
+	}
+
+	@Override
+	public String processSql(String sql, RowSelection selection) {
+		final boolean hasFirstRow = LimitHelper.hasFirstRow( selection );
+		final boolean hasMaxRows = LimitHelper.hasMaxRows( selection );
+
+		if ( !hasMaxRows ) {
+			return sql;
+		}
+
+		return processSql( sql, getForUpdateIndex( sql ), hasFirstRow );
+	}
+
+	@Override
+	public String processSql(String sql, QueryParameters queryParameters) {
+		final RowSelection selection = queryParameters.getRowSelection();
+
+		final boolean hasFirstRow = LimitHelper.hasFirstRow( selection );
+		final boolean hasMaxRows = LimitHelper.hasMaxRows( selection );
+
+		if ( !hasMaxRows ) {
+			return sql;
+		}
+
+		final LockOptions lockOptions = queryParameters.getLockOptions();
+		if ( lockOptions != null ) {
+			final LockMode lockMode = lockOptions.getLockMode();
+			switch ( lockMode ) {
+				case UPGRADE:
+				case PESSIMISTIC_READ:
+				case PESSIMISTIC_WRITE:
+				case UPGRADE_NOWAIT:
+				case FORCE:
+				case PESSIMISTIC_FORCE_INCREMENT:
+				case UPGRADE_SKIPLOCKED:
+					return processSql( sql, selection );
+				default:
+					return processSqlOffsetFetch( sql, hasFirstRow );
+			}
+		}
+		return processSqlOffsetFetch( sql, hasFirstRow );
+	}
+
+	private String processSqlOffsetFetch(String sql, boolean hasFirstRow) {
+
+		final int forUpdateLastIndex = getForUpdateIndex( sql );
+
+		if ( forUpdateLastIndex > -1 ) {
+			return processSql( sql, forUpdateLastIndex, hasFirstRow );
+		}
+
+		bindLimitParametersInReverseOrder = false;
+		useMaxForLimit = false;
+
+		sql = normalizeStatement( sql );
+		final int offsetFetchLength;
+		final String offsetFetchString;
+		if ( hasFirstRow ) {
+			offsetFetchString = " offset ? rows fetch next ? rows only";
+		}
+		else {
+			offsetFetchString = " fetch first ? rows only";
+		}
+		offsetFetchLength = sql.length() + offsetFetchString.length();
+
+		return new StringBuilder( offsetFetchLength ).append( sql ).append( offsetFetchString ).toString();
+	}
+
+	private String processSql(String sql, int forUpdateIndex, boolean hasFirstRow) {
+		bindLimitParametersInReverseOrder = true;
+		useMaxForLimit = true;
+		sql = normalizeStatement( sql );
+
+		String forUpdateClause = null;
+		boolean isForUpdate = false;
+		if ( forUpdateIndex > -1 ) {
+			// save 'for update ...' and then remove it
+			forUpdateClause = sql.substring( forUpdateIndex );
+			sql = sql.substring( 0, forUpdateIndex - 1 );
+			isForUpdate = true;
+		}
+
+		final StringBuilder pagingSelect;
+
+		final int forUpdateClauseLength;
+		if ( forUpdateClause == null ) {
+			forUpdateClauseLength = 0;
+		}
+		else {
+			forUpdateClauseLength = forUpdateClause.length() + 1;
+		}
+
+		if ( hasFirstRow ) {
+			pagingSelect = new StringBuilder( sql.length() + forUpdateClauseLength + 98 );
+			pagingSelect.append( "select * from ( select row_.*, rownum rownum_ from ( " );
+			pagingSelect.append( sql );
+			pagingSelect.append( " ) row_ where rownum <= ?) where rownum_ > ?" );
+		}
+		else {
+			pagingSelect = new StringBuilder( sql.length() + forUpdateClauseLength + 37 );
+			pagingSelect.append( "select * from ( " );
+			pagingSelect.append( sql );
+			pagingSelect.append( " ) where rownum <= ?" );
+		}
+
+		if ( isForUpdate ) {
+			pagingSelect.append( " " );
+			pagingSelect.append( forUpdateClause );
+		}
+
+		return pagingSelect.toString();
+	}
+
+	private String normalizeStatement(String sql) {
+		return sql.trim().replaceAll( "\\s+", " " );
+	}
+
+	private int getForUpdateIndex(String sql) {
+		final int forUpdateLastIndex = sql.toLowerCase( Locale.ROOT ).lastIndexOf( "for update" );
+		// We need to recognize cases like : select a from t where b = 'for update';
+		final int lastIndexOfQuote = sql.lastIndexOf( "'" );
+		if ( forUpdateLastIndex > -1 ) {
+			if ( lastIndexOfQuote == -1 ) {
+				return forUpdateLastIndex;
+			}
+			if ( lastIndexOfQuote > forUpdateLastIndex ) {
+				return -1;
+			}
+			return forUpdateLastIndex;
+		}
+		return forUpdateLastIndex;
+	}
+
+	@Override
+	public final boolean supportsLimit() {
+		return true;
+	}
+
+	@Override
+	public boolean bindLimitParametersInReverseOrder() {
+		return bindLimitParametersInReverseOrder;
+	}
+
+	@Override
+	public boolean useMaxForLimit() {
+		return useMaxForLimit;
+	}
+
+
+}

hibernate-core/src/main/java/org/hibernate/loader/Loader.java

@@ -2021,7 +2021,7 @@ public abstract class Loader {
 		final LimitHandler limitHandler = getLimitHandler(
 				queryParameters.getRowSelection()
 		);
-		String sql = limitHandler.processSql( queryParameters.getFilteredSQL(), queryParameters.getRowSelection() );
+		String sql = limitHandler.processSql( queryParameters.getFilteredSQL(), queryParameters );
 
 		// Adding locks and comments.
 		sql = preprocessSQL( sql, queryParameters, getFactory(), afterLoadActions );

hibernate-core/src/main/java/org/hibernate/loader/plan/exec/internal/AbstractLoadPlanBasedLoader.java

@@ -149,7 +149,7 @@ public abstract class AbstractLoadPlanBasedLoader {
 		final LimitHandler limitHandler = getLimitHandler(
 				queryParameters.getRowSelection()
 		);
-		String sql = limitHandler.processSql( queryParameters.getFilteredSQL(), queryParameters.getRowSelection() );
+		String sql = limitHandler.processSql( queryParameters.getFilteredSQL(), queryParameters );
 
 		// Adding locks and comments.
 		sql = session.getJdbcServices().getJdbcEnvironment().getDialect()