Fix order by rendering for queries containing UNION.

Make sure to append space after order by clause and fix alias detection for wrapped sub select.
Also make sure to ignore alias used in subselect so they do not conflict with root ones.

Render order by only on full select if set operator is present in EQL.

Original pull request: #3429
Closes #3427

Author: christophstrobl

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/EqlSortedQueryTransformer.java

@@ -23,13 +23,15 @@
 import org.springframework.data.jpa.repository.query.QueryRenderer.QueryRendererBuilder;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
 
 /**
  * An ANTLR {@link org.antlr.v4.runtime.tree.ParseTreeVisitor} that transforms a parsed EQL query by applying
  * {@link Sort}.
  *
  * @author Greg Turnquist
  * @author Mark Paluch
+ * @author Christoph Strobl
  * @since 3.2
  */
 @SuppressWarnings("ConstantValue")
@@ -67,7 +69,7 @@ public QueryRendererBuilder visitSelect_statement(EqlParser.Select_statementCont
 			builder.appendExpression(visit(ctx.having_clause()));
 		}
 
-		doVisitOrderBy(builder, ctx);
+		doVisitOrderBy(builder, ctx, ObjectUtils.isEmpty(ctx.setOperator()) ? this.sort : Sort.unsorted());
 
 		for (int i = 0; i < ctx.setOperator().size(); i++) {
 
@@ -78,7 +80,7 @@ public QueryRendererBuilder visitSelect_statement(EqlParser.Select_statementCont
 		return builder;
 	}
 
-	private void doVisitOrderBy(QueryRendererBuilder builder, EqlParser.Select_statementContext ctx) {
+	private void doVisitOrderBy(QueryRendererBuilder builder, EqlParser.Select_statementContext ctx, Sort sort) {
 
 		if (ctx.orderby_clause() != null) {
 			QueryTokenStream existingOrder = visit(ctx.orderby_clause());

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/HqlSortedQueryTransformer.java

@@ -23,6 +23,7 @@
 import org.springframework.data.jpa.repository.query.QueryRenderer.QueryRendererBuilder;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
 
 /**
  * An ANTLR {@link org.antlr.v4.runtime.tree.ParseTreeVisitor} that transforms a parsed HQL query.
@@ -46,8 +47,72 @@ class HqlSortedQueryTransformer extends HqlQueryRenderer {
 		this.primaryFromAlias = primaryFromAlias;
 	}
 
+
+	public QueryTokenStream visitQueryExpression(HqlParser.QueryExpressionContext ctx) {
+
+		if(ObjectUtils.isEmpty(ctx.setOperator())) {
+			return super.visitQueryExpression(ctx);
+		}
+
+		QueryRendererBuilder builder = QueryRenderer.builder();
+		if (ctx.withClause() != null) {
+			builder.appendExpression(visit(ctx.withClause()));
+		}
+
+		builder.append(visitOrderedQuery(ctx.orderedQuery(0), Sort.unsorted()));
+
+		for (int i = 1; i < ctx.orderedQuery().size(); i++) {
+
+			builder.append(visit(ctx.setOperator(i - 1)));
+			builder.append(visit(ctx.orderedQuery(i)));
+		}
+
+
+		return builder;
+	}
+
 	@Override
 	public QueryRendererBuilder visitOrderedQuery(HqlParser.OrderedQueryContext ctx) {
+		return visitOrderedQuery(ctx, this.sort);
+	}
+
+	@Override
+	public QueryTokenStream visitJoinPath(HqlParser.JoinPathContext ctx) {
+
+		QueryTokenStream tokens = super.visitJoinPath(ctx);
+
+		if (ctx.variable() != null  && !isSubquery(ctx)) {
+			transformerSupport.registerAlias(tokens.getLast());
+		}
+
+		return tokens;
+	}
+
+	@Override
+	public QueryTokenStream visitJoinSubquery(HqlParser.JoinSubqueryContext ctx) {
+
+		QueryTokenStream tokens = super.visitJoinSubquery(ctx);
+
+		if (ctx.variable() != null && !tokens.isEmpty()  && !isSubquery(ctx)) {
+			transformerSupport.registerAlias(tokens.getLast());
+		}
+
+		return tokens;
+	}
+
+	@Override
+	public QueryTokenStream visitVariable(HqlParser.VariableContext ctx) {
+
+		QueryTokenStream tokens = super.visitVariable(ctx);
+
+		if (ctx.identifier() != null && !tokens.isEmpty()  && !isSubquery(ctx)) {
+			transformerSupport.registerAlias(tokens.getLast());
+		}
+
+		return tokens;
+	}
+
+	private QueryRendererBuilder visitOrderedQuery(HqlParser.OrderedQueryContext ctx, Sort sort) {
 
 		QueryRendererBuilder builder = QueryRenderer.builder();
 
@@ -95,40 +160,4 @@ public QueryRendererBuilder visitOrderedQuery(HqlParser.OrderedQueryContext ctx)
 		return builder;
 	}
 
-	@Override
-	public QueryTokenStream visitJoinPath(HqlParser.JoinPathContext ctx) {
-
-		QueryTokenStream tokens = super.visitJoinPath(ctx);
-
-		if (ctx.variable() != null) {
-			transformerSupport.registerAlias(tokens.getLast());
-		}
-
-		return tokens;
-	}
-
-	@Override
-	public QueryTokenStream visitJoinSubquery(HqlParser.JoinSubqueryContext ctx) {
-
-		QueryTokenStream tokens = super.visitJoinSubquery(ctx);
-
-		if (ctx.variable() != null && !tokens.isEmpty()) {
-			transformerSupport.registerAlias(tokens.getLast());
-		}
-
-		return tokens;
-	}
-
-	@Override
-	public QueryTokenStream visitVariable(HqlParser.VariableContext ctx) {
-
-		QueryTokenStream tokens = super.visitVariable(ctx);
-
-		if (ctx.identifier() != null && !tokens.isEmpty()) {
-			transformerSupport.registerAlias(tokens.getLast());
-		}
-
-		return tokens;
-	}
-
 }

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryTransformerSupport.java

@@ -53,7 +53,7 @@ void registerAlias(QueryToken token) {
 	 * @param sort
 	 * @return
 	 */
-	List<QueryToken> orderBy(String primaryFromAlias, Sort sort) {
+	List<QueryToken> orderBy(@Nullable String primaryFromAlias, Sort sort) {
 
 		List<QueryToken> tokens = new ArrayList<>();
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/EqlQueryTransformerTests.java

@@ -759,6 +759,15 @@ void sortingRecognizesJoinAliases() {
 				""");
 	}
 
+	@Test // GH-3427
+	void sortShouldBeAppendedToFullSelectOnlyInCaseOfSetOperator() {
+
+		String source = "SELECT tb FROM Test tb WHERE (tb.type='A') UNION SELECT tb FROM Test tb WHERE (tb.type='B')";
+		String target = createQueryFor(source, Sort.by("Type").ascending());
+
+		assertThat(target).isEqualTo("SELECT tb FROM Test tb WHERE (tb.type = 'A') UNION SELECT tb FROM Test tb WHERE (tb.type = 'B') order by tb.Type asc");
+	}
+
 	static Stream<Arguments> queriesWithReservedWordsAsIdentifiers() {
 
 		return Stream.of( //

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/HqlQueryTransformerTests.java

@@ -17,18 +17,22 @@
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
 import org.assertj.core.api.SoftAssertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.domain.JpaSort;
 import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
 
 /**
  * Verify that HQL queries are properly transformed through the {@link JpaQueryEnhancer} and the
@@ -1061,6 +1065,40 @@ void createsCountQueryUsingAliasCorrectly() {
 				"select count(distinct a, count(b)) from Employee AS __ GROUP BY n");
 	}
 
+	@Test // GH-3427
+	void sortShouldBeAppendedWithSpacingInCaseOfSetOperator() {
+
+        String source = "SELECT tb FROM Test tb WHERE (tb.type='A') UNION SELECT tb FROM Test tb WHERE (tb.type='B')";
+		String target = createQueryFor(source, Sort.by("Type").ascending());
+		
+		assertThat(target).isEqualTo("SELECT tb FROM Test tb WHERE (tb.type = 'A') UNION SELECT tb FROM Test tb WHERE (tb.type = 'B') order by tb.Type asc");
+	}
+
+	@ParameterizedTest // GH-3427
+	@ValueSource(strings = {"", "res"})
+	void sortShouldBeAppendedToSubSelectWithSetOperatorInSubselect(String alias) {
+
+		String prefix = StringUtils.hasText(alias) ? (alias + ".") : "";
+		String source = "SELECT %sname FROM (SELECT c.name as name FROM Category c UNION SELECT t.name as name FROM Tag t)".formatted(prefix);
+		if(StringUtils.hasText(alias)) {
+			source = source + " %s".formatted(alias);
+		}
+
+		String target = createQueryFor(source, Sort.by("name").ascending());
+
+		assertThat(target).contains(" UNION SELECT ").doesNotContainPattern(Pattern.compile(".*\\SUNION"));
+		assertThat(target).endsWith("order by %sname asc".formatted(prefix)).satisfies(it -> {
+			Pattern pattern = Pattern.compile("order by %sname".formatted(prefix));
+			Matcher matcher = pattern.matcher(target);
+			int count = 0;
+			while(matcher.find()) {
+				count++;
+			}
+			assertThat(count).describedAs("Found order by clause more than once in: \n%s", it).isOne();
+		});
+
+	}
+
 	private void assertCountQuery(String originalQuery, String countQuery) {
 		assertThat(createCountQueryFor(originalQuery)).isEqualTo(countQuery);
 	}