Support empty Array of Struct / Do not support null-valued Array of S…

…truct according to the behaviour in realworld Spanner fix: GoogleCloudPlatform#165
MITSUBOSHI · Dec 5, 2024 · 205bd8a · 205bd8a
1 parent 0084b2c
commit 205bd8a
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Showing 4 changed files with 24 additions and 12 deletions.
diff --git a/backend/query/query_validator.cc b/backend/query/query_validator.cc
@@ -505,8 +505,8 @@ absl::Status QueryValidator::VisitResolvedLiteral(
     const zetasql::ResolvedLiteral* node) {
   if (node->type()->IsArray() &&
       node->type()->AsArray()->element_type()->IsStruct() &&
-      node->value().is_empty_array()) {
-    return error::UnsupportedArrayConstructorSyntaxForEmptyStructArray();
+      node->value().is_null()) {
+    return error::UnsupportedArrayConstructorSyntaxForNullValuedStructArray();
   }
 
   return DefaultVisit(node);

diff --git a/common/errors.cc b/common/errors.cc
@@ -2884,11 +2884,11 @@ absl::Status UnsupportedReturnStructAsColumn() {
       "value. Rewrite the query to flatten the struct fields in the result.");
 }
 
-absl::Status UnsupportedArrayConstructorSyntaxForEmptyStructArray() {
+absl::Status UnsupportedArrayConstructorSyntaxForNullValuedStructArray() {
   return absl::Status(
       absl::StatusCode::kUnimplemented,
       "Unsupported query shape: Spanner does not support array constructor "
-      "syntax for an empty array where array elements are Structs.");
+      "syntax for a null-valued array of struct.");
 }
 
 absl::Status UnsupportedFeatureSafe(absl::string_view feature_type,

diff --git a/common/errors.h b/common/errors.h
@@ -695,7 +695,7 @@ absl::Status ReadOnlyTransactionDoesNotSupportReadWriteOnlyFunctions(
 absl::Status CannotInsertDuplicateKeyInsertOrUpdateDml(absl::string_view key);
 // Unsupported query shape errors.
 absl::Status UnsupportedReturnStructAsColumn();
-absl::Status UnsupportedArrayConstructorSyntaxForEmptyStructArray();
+absl::Status UnsupportedArrayConstructorSyntaxForNullValuedStructArray();
 absl::Status UnsupportedFeatureSafe(absl::string_view feature_type,
                                     absl::string_view info_message);
 absl::Status UnsupportedFunction(absl::string_view function_name);

diff --git a/tests/conformance/cases/query.cc b/tests/conformance/cases/query.cc
@@ -555,16 +555,13 @@ TEST_P(QueryTest, CanReturnArrayOfStructTypedColumns) {
       IsOkAndHoldsRow({Value(std::vector<SimpleStruct>{SimpleStruct{1}})}));
 }
 
-TEST_P(QueryTest, CannotQueryArrayOfEmptyStruct) {
+TEST_P(QueryTest, CanQueryArrayOfEmptyStruct) {
   // Spanner PG dialect doesn't support STRUCT.
   if (GetParam() != database_api::DatabaseDialect::POSTGRESQL) {
+    using SimpleStruct = std::tuple<int64_t>;
     EXPECT_THAT(
-        Query("SELECT ARRAY<STRUCT<int64_val INT64>>[]"),
-        StatusIs(
-            absl::StatusCode::kUnimplemented,
-            "Unsupported query shape: Spanner does not support array "
-            "constructor "
-            "syntax for an empty array where array elements are Structs."));
+        Query("SELECT ARRAY<STRUCT<INT64>>[]"),
+        IsOkAndHoldsRow({Value(std::vector<SimpleStruct>{SimpleStruct{}})}));
   }
 
   std::string query = "SELECT ARRAY<INT64>[]";
@@ -574,6 +571,21 @@ TEST_P(QueryTest, CannotQueryArrayOfEmptyStruct) {
   EXPECT_THAT(Query(query), IsOkAndHoldsRow({Value(std::vector<int64_t>{})}));
 }
 
+TEST_P(QueryTest, CannotQueryNullValuedArrayOfStruct) {
+  // Spanner PG dialect doesn't support STRUCT and array subquery expressions.
+  if (GetParam() == database_api::DatabaseDialect::POSTGRESQL) {
+    GTEST_SKIP();
+  }
+
+  EXPECT_THAT(
+        Query("SELECT IF(false, ARRAY<STRUCT<INT64>>[], null)"),
+        StatusIs(
+            absl::StatusCode::kUnimplemented,
+            "Unsupported query shape: Spanner does not support array "
+            "constructor "
+            "syntax for a null-valued array of struct."));
+}
+
 TEST_P(QueryTest, QueryColumnCannotBeStruct) {
   // Spanner PG dialect doesn't support STRUCT.
   if (GetParam() == database_api::DatabaseDialect::POSTGRESQL) {