HHH-18916 - extends addQueryHints behavior

QUERY_PATTERN regex handles queries with natural, left/right, inner/outer join

Add unit test to check existing behavior

Author: rguihard

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

@@ -278,7 +278,8 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 
 	private static final Pattern ESCAPE_CLOSING_COMMENT_PATTERN = Pattern.compile( "\\*/" );
 	private static final Pattern ESCAPE_OPENING_COMMENT_PATTERN = Pattern.compile( "/\\*" );
-	private static final Pattern QUERY_PATTERN = Pattern.compile( "^\\s*(select\\b.+?\\bfrom\\b.+?)(\\b(where|join)\\b.+?)$" );
+	private static final Pattern QUERY_PATTERN = Pattern.compile(
+		"^\\s*(select\\b.+?\\bfrom\\b.+?)(\\b(?:natural )?(?:left |right )?(?:inner |outer )?join.+?\\b)?(\\bwhere\\b.+?)$");
 
 	private static final CoreMessageLogger LOG = Logger.getMessageLogger( MethodHandles.lookup(), CoreMessageLogger.class, Dialect.class.getName() );
 
@@ -4767,13 +4768,16 @@ public String addSqlHintOrComment(
 	public static String addQueryHints(String query, String hints) {
 		Matcher matcher = QUERY_PATTERN.matcher( query );
 		if ( matcher.matches() && matcher.groupCount() > 1 ) {
-			String startToken = matcher.group( 1 );
-			String endToken = matcher.group( 2 );
+			final String startToken = matcher.group(1);
+			// Null if there is no join in the query
+			final String joinToken = Objects.toString(matcher.group(2), "");
+			final String endToken = matcher.group(3);
 
 			return startToken +
 					" use index (" +
 					hints +
 					") " +
+					joinToken +
 					endToken;
 		}
 		else {

hibernate-core/src/test/java/org/hibernate/dialect/DialectTest.java

@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.dialect;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.stream.Stream;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+/**
+ * Check if IndexQueryHintHandler handles correctly simple query and query with JOIN
+ *
+ * @author Rguihard
+ */
+class DialectTest {
+
+	static Stream<Arguments> _addQueryHints() {
+		final Stream.Builder<Arguments> builder = Stream.builder();
+
+		final String hints = "MY_INDEX";
+		final String simpleQuery = "select COUNT(*) from TEST t1_0 where column1 = 'value'";
+		builder.add(
+			Arguments.of("Simple query : hint",
+				"select COUNT(*) from TEST t1_0  use index (MY_INDEX) where column1 = 'value'", simpleQuery, hints));
+		final String joinQueryUsing = "select COUNT(*) from TEST t1_0 join TEST2 t2_0 using(column2) where field = 'value'";
+		builder.add(Arguments.of("Join query with using : hint",
+			"select COUNT(*) from TEST t1_0  use index (MY_INDEX) join TEST2 t2_0 using(column2) where field = 'value'",
+			joinQueryUsing, hints));
+		final String joinQueryOn = "select COUNT(*) from TEST t1_0 join TEST2 t2_0 on t1_0.column2 = t2_0.column2 where field = 'value'";
+		builder.add(Arguments.of("Join query with on : hint",
+			"select COUNT(*) from TEST t1_0  use index (MY_INDEX) join TEST2 t2_0 on t1_0.column2 = t2_0.column2 where field = 'value'",
+			joinQueryOn, hints));
+		final String leftJoinQuery = "select COUNT(*) from TEST t1_0 left join TEST2 t2_0 on t1_0.column2 = t2_0.column2 and t1_0.column3 = t2_0.column3 where field = 'value'";
+		builder.add(Arguments.of("Left join query with on : hint",
+			"select COUNT(*) from TEST t1_0  use index (MY_INDEX) left join TEST2 t2_0 on t1_0.column2 = t2_0.column2 and t1_0.column3 = t2_0.column3 where field = 'value'",
+			leftJoinQuery, hints));
+
+		return builder.build();
+	}
+
+	@MethodSource("_addQueryHints")
+	@ParameterizedTest
+	void addQueryHints(String description, String expected, String query, String hints) {
+		final String queryWithHint = MySQLDialect.addQueryHints(query, hints);
+		assertEquals(expected, queryWithHint, description);
+	}
+
+}