Backoff JSqlParserQueryEnhancer if query type is not a supported quer…

…y type.

We now backoff from enhancing queries if the query type is not supported (e.g. TRUNCATE).

Closes #3038

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

@@ -96,7 +96,7 @@ private ParsedType detectParsedType() {
 			} else if (statement instanceof Merge) {
 				return ParsedType.MERGE;
 			} else {
-				return ParsedType.SELECT;
+				return ParsedType.OTHER;
 			}
 		} catch (JSQLParserException e) {
 			throw new IllegalArgumentException("The query you provided is not a valid SQL Query!", e);
@@ -314,10 +314,10 @@ private String detectAlias(String query) {
 			Select selectStatement = parseSelectStatement(query);
 
 			/*
-			For all the other types ({@link ValuesStatement} and {@link SetOperationList}) it does not make sense to provide
-			alias since:
-			* ValuesStatement has no alias
-			* SetOperation can have multiple alias for each operation item
+			 * For all the other types ({@link ValuesStatement} and {@link SetOperationList}) it does not make sense to provide
+			 * alias since:
+			 * ValuesStatement has no alias
+			 * SetOperation can have multiple alias for each operation item
 			 */
 			if (!(selectStatement.getSelectBody() instanceof PlainSelect)) {
 				return null;
@@ -516,10 +516,11 @@ public DeclaredQuery getQuery() {
 	 * <li>{@code ParsedType.SELECT}: means the top level statement is {@link Select}</li>
 	 * <li>{@code ParsedType.INSERT}: means the top level statement is {@link Insert}</li>
 	 * <li>{@code ParsedType.MERGE}: means the top level statement is {@link Merge}</li>
+	 * <li>{@code ParsedType.OTHER}: means the top level statement is a different top-level type</li>
 	 * </ul>
 	 */
 	enum ParsedType {
-		DELETE, UPDATE, SELECT, INSERT, MERGE;
+		DELETE, UPDATE, SELECT, INSERT, MERGE, OTHER;
 	}
 
 }

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

@@ -191,6 +191,23 @@ void multipleWithStatementsWorks() {
 		assertThat(queryEnhancer.hasConstructorExpression()).isFalse();
 	}
 
+	@Test // GH-3038
+	void truncateStatementShouldWork() {
+
+		StringQuery stringQuery = new StringQuery("TRUNCATE TABLE foo", true);
+		QueryEnhancer queryEnhancer = QueryEnhancerFactory.forQuery(stringQuery);
+
+		assertThat(stringQuery.getAlias()).isNull();
+		assertThat(stringQuery.getProjection()).isEmpty();
+		assertThat(stringQuery.hasConstructorExpression()).isFalse();
+
+		assertThat(queryEnhancer.applySorting(Sort.by("day").descending())).isEqualTo("TRUNCATE TABLE foo");
+		assertThat(queryEnhancer.getJoinAliases()).isEmpty();
+		assertThat(queryEnhancer.detectAlias()).isNull();
+		assertThat(queryEnhancer.getProjection()).isEmpty();
+		assertThat(queryEnhancer.hasConstructorExpression()).isFalse();
+	}
+
 	@ParameterizedTest // GH-2641
 	@MethodSource("mergeStatementWorksSource")
 	void mergeStatementWorksWithJSqlParser(String query, String alias) {