Improvement #8722 - The "IF NOT EXISTS" clause is missing for DECLARE FILTER

Author: asfernandes

src/dsql/DdlNodes.epp

@@ -10758,6 +10758,12 @@ void CreateFilterNode::execute(thread_db* tdbb, DsqlCompilerScratch* /*dsqlScrat
 {
 	Attachment* const attachment = transaction->tra_attachment;
 	const MetaString& ownerName = attachment->getEffectiveUserName();
+	const QualifiedName qualifiedName(name);
+
+	if (createIfNotExistsOnly && !DYN_UTIL_check_unique_name_nothrow(tdbb, transaction, qualifiedName, obj_blob_filter))
+		return;
+
+	DYN_UTIL_check_unique_name(tdbb, transaction, qualifiedName, obj_blob_filter);
 
 	// run all statements under savepoint control
 	AutoSavePoint savePoint(tdbb, transaction);

src/dsql/DdlNodes.h

@@ -2072,6 +2072,7 @@ class CreateFilterNode final : public DdlNode
 	NestConst<NameNumber> outputFilter;
 	Firebird::string entryPoint;
 	Firebird::string moduleName;
+	bool createIfNotExistsOnly = false;
 };
 
 

src/dsql/parse-conflicts.txt

@@ -1 +1 @@
-132 shift/reduce conflicts, 13 reduce/reduce conflicts.
+133 shift/reduce conflicts, 13 reduce/reduce conflicts.

src/dsql/parse.y

@@ -822,6 +822,7 @@ using namespace Firebird;
 	Jrd::CreateAlterExceptionNode* createAlterExceptionNode;
 	Jrd::CreateAlterSequenceNode* createAlterSequenceNode;
 	Jrd::CreateAlterSchemaNode* createAlterSchemaNode;
+	Jrd::CreateFilterNode* createFilterNode;
 	Jrd::CreateShadowNode* createShadowNode;
 	Firebird::Array<Jrd::CreateAlterPackageNode::Item>* packageItems;
 	Jrd::ExceptionArray* exceptionArray;
@@ -1469,7 +1470,12 @@ declare
 
 %type <ddlNode> declare_clause
 declare_clause
-	: FILTER filter_decl_clause				{ $$ = $2; }
+	: FILTER if_not_exists_opt filter_decl_clause
+		{
+			const auto node = $3;
+			node->createIfNotExistsOnly = $2;
+			$$ = node;
+		}
 	| EXTERNAL FUNCTION if_not_exists_opt udf_decl_clause
 		{
 			const auto node = $4;
@@ -1570,7 +1576,7 @@ return_mechanism
 	;
 
 
-%type <ddlNode> filter_decl_clause
+%type <createFilterNode> filter_decl_clause
 filter_decl_clause
 	: symbol_filter_name
 		INPUT_TYPE blob_filter_subtype

src/include/firebird/impl/msg/dyn.h

@@ -311,3 +311,4 @@ FB_IMPL_MSG(DYN, 318, dyn_cannot_drop_non_emptyschema, -607, "HY", "000", "Canno
 FB_IMPL_MSG(DYN, 319, dyn_cannot_mod_obj_sys_schema, -607, "28", "000", "Cannot CREATE/ALTER/DROP @1 in SYSTEM schema")
 FB_IMPL_MSG(DYN, 320, dyn_cannot_create_reserved_schema, -607, "HY", "000", "Schema name @1 is reserved and cannot be created")
 FB_IMPL_MSG(DYN, 321, dyn_cannot_infer_schema, -901, "42", "000", "Cannot infer schema name as there is no valid schema in the search path")
+FB_IMPL_MSG_SYMBOL(DYN, 322, dyn_dup_blob_filter, "Blob filter @1 already exists")

src/jrd/dyn_util.epp

@@ -283,6 +283,24 @@ bool DYN_UTIL_check_unique_name_nothrow(thread_db* tdbb, jrd_tra* transaction,
 			break;
 		}
 
+		case obj_blob_filter:
+		{
+			fb_assert(object_name.schema.isEmpty());
+
+			static const CachedRequestId schemaHandleId;
+			requestHandle.reset(tdbb, schemaHandleId);
+
+			FOR(REQUEST_HANDLE requestHandle TRANSACTION_HANDLE transaction)
+				FIL IN RDB$FILTERS
+				WITH FIL.RDB$FUNCTION_NAME EQ object_name.object.c_str()
+			{
+				*errorCode = 322;	// isc_dyn_dup_blob_filter
+			}
+			END_FOR
+
+			break;
+		}
+
 		default:
 			fb_assert(false);
 	}