Add IStatement::getFlags() to help user make a solution what to do with SQL statement

src/common/StatementMetadata.cpp

@@ -64,6 +64,9 @@ unsigned StatementMetadata::buildInfoItems(Array<UCHAR>& items, unsigned flags)
 	if (flags & IStatement::PREPARE_PREFETCH_TYPE)
 		items.add(isc_info_sql_stmt_type);
 
+	if (flags & IStatement::PREPARE_PREFETCH_FLAGS)
+		items.add(isc_info_sql_stmt_flags);
+
 	if (flags & IStatement::PREPARE_PREFETCH_INPUT_PARAMETERS)
 	{
 		items.add(isc_info_sql_bind);
@@ -100,6 +103,10 @@ unsigned StatementMetadata::buildInfoFlags(unsigned itemsLength, const UCHAR* it
 				flags |= IStatement::PREPARE_PREFETCH_TYPE;
 				break;
 
+			case isc_info_sql_stmt_flags:
+				flags |= IStatement::PREPARE_PREFETCH_FLAGS;
+				break;
+
 			case isc_info_sql_get_plan:
 				flags |= IStatement::PREPARE_PREFETCH_LEGACY_PLAN;
 				break;
@@ -137,6 +144,21 @@ unsigned StatementMetadata::getType()
 	return type.value;
 }
 
+unsigned StatementMetadata::getFlags()
+{
+	if (!flags.specified)
+	{
+		UCHAR info[] = {isc_info_sql_stmt_flags};
+		UCHAR result[16];
+
+		getAndParse(sizeof(info), info, sizeof(result), result);
+
+		fb_assert(flags.specified);
+	}
+
+	return flags.value;
+}
+
 // Get statement plan.
 const char* StatementMetadata::getPlan(bool detailed)
 {
@@ -227,6 +249,10 @@ void StatementMetadata::parse(unsigned bufferLength, const UCHAR* buffer)
 				type = getNumericInfo(&buffer);
 				break;
 
+			case isc_info_sql_stmt_flags:
+				flags = getNumericInfo(&buffer);
+				break;
+
 			case isc_info_sql_get_plan:
 			case isc_info_sql_explain_plan:
 			{

src/common/StatementMetadata.h

@@ -66,6 +66,7 @@ public:
 	static unsigned buildInfoFlags(unsigned itemsLength, const UCHAR* items);
 
 	unsigned getType();
+	unsigned getFlags();
 	const char* getPlan(bool detailed);
 	IMessageMetadata* getInputMetadata();
 	IMessageMetadata* getOutputMetadata();
@@ -81,7 +82,7 @@ private:
 
 private:
 	IStatement* statement;
-	Nullable<unsigned> type;
+	Nullable<unsigned> type, flags;
 	string legacyPlan, detailedPlan;
 	RefPtr<Parameters> inputParameters, outputParameters;
 };

src/dsql/dsql.cpp

@@ -1713,6 +1713,7 @@ static void sql_info(thread_db* tdbb,
 	{
 		ULONG length;
 		USHORT number;
+		ULONG value;
 		const UCHAR item = *items++;
 
 		switch (item)
@@ -1730,6 +1731,26 @@ static void sql_info(thread_db* tdbb,
 			*info++ = item;
 			break;
 
+		case isc_info_sql_stmt_flags:
+			value = IStatement::STATEMENT_REPEAT_EXECUTE;
+			switch (statement->getType())
+			{
+			case DsqlCompiledStatement::TYPE_CREATE_DB:
+			case DsqlCompiledStatement::TYPE_DDL:
+				value &= ~IStatement::STATEMENT_REPEAT_EXECUTE;
+				break;
+			case DsqlCompiledStatement::TYPE_SELECT:
+			case DsqlCompiledStatement::TYPE_SELECT_UPD:
+			case DsqlCompiledStatement::TYPE_SELECT_BLOCK:
+				value |= IStatement::STATEMENT_HAS_CURSOR;
+				break;
+			}
+			length = put_vax_long(buffer, value);
+			info = put_item(item, length, buffer, info, end_info);
+			if (!info)
+				return;
+			break;
+
 		case isc_info_sql_stmt_type:
 			switch (statement->getType())
 			{

src/include/firebird/Provider.h

@@ -151,12 +151,18 @@ public:
 	static const unsigned PREPARE_PREFETCH_LEGACY_PLAN			= 0x08;
 	static const unsigned PREPARE_PREFETCH_DETAILED_PLAN		= 0x10;
 	static const unsigned PREPARE_PREFETCH_AFFECTED_RECORDS		= 0x20;	// not used yet
+	static const unsigned PREPARE_PREFETCH_FLAGS				= 0x40;
 	static const unsigned PREPARE_PREFETCH_METADATA =
-		PREPARE_PREFETCH_TYPE | PREPARE_PREFETCH_INPUT_PARAMETERS | PREPARE_PREFETCH_OUTPUT_PARAMETERS;
+		PREPARE_PREFETCH_TYPE | PREPARE_PREFETCH_FLAGS |
+		PREPARE_PREFETCH_INPUT_PARAMETERS | PREPARE_PREFETCH_OUTPUT_PARAMETERS;
 	static const unsigned PREPARE_PREFETCH_ALL =
 		PREPARE_PREFETCH_METADATA | PREPARE_PREFETCH_LEGACY_PLAN | PREPARE_PREFETCH_DETAILED_PLAN |
 		PREPARE_PREFETCH_AFFECTED_RECORDS;
 
+	// Statement flags.
+	static const unsigned STATEMENT_HAS_CURSOR 					= 0x01;
+	static const unsigned STATEMENT_REPEAT_EXECUTE			 	= 0x02;
+
 	virtual void FB_CARG getInfo(IStatus* status,
 								 unsigned int itemsLength, const unsigned char* items,
 								 unsigned int bufferLength, unsigned char* buffer) = 0;
@@ -171,8 +177,9 @@ public:
 		FbMessage* in, IMessageMetadata* out) = 0;
 	virtual void FB_CARG setCursorName(IStatus* status, const char* name) = 0;
 	virtual void FB_CARG free(IStatus* status) = 0;
+	virtual unsigned FB_CARG getFlags(IStatus* status) = 0;
 };
-#define FB_STATEMENT_VERSION (FB_REFCOUNTED_VERSION + 10)
+#define FB_STATEMENT_VERSION (FB_REFCOUNTED_VERSION + 11)
 
 class IRequest : public IRefCounted
 {

src/jrd/EngineInterface.h

@@ -190,6 +190,7 @@ public:
 	virtual JResultSet* FB_CARG openCursor(Firebird::IStatus* status,
 		Firebird::ITransaction* transaction, Firebird::FbMessage* in, Firebird::IMessageMetadata* out);
 	virtual void FB_CARG setCursorName(Firebird::IStatus* status, const char* name);
+	virtual unsigned FB_CARG getFlags(Firebird::IStatus* status);
 
 public:
 	JStatement(dsql_req* handle, JAttachment* ja, Firebird::Array<UCHAR>& meta)

src/jrd/inf_pub.h

@@ -390,6 +390,7 @@ enum info_db_provider
 #define isc_info_sql_batch_fetch	  24
 #define isc_info_sql_relation_alias		25
 #define isc_info_sql_explain_plan		26
+#define isc_info_sql_stmt_flags         27
 
 /*********************************/
 /* SQL information return values */

src/jrd/jrd.cpp

@@ -4573,6 +4573,37 @@ unsigned JStatement::getType(IStatus* userStatus)
 }
 
 
+unsigned JStatement::getFlags(IStatus* userStatus)
+{
+	unsigned ret = 0;
+
+	try
+	{
+		EngineContextHolder tdbb(userStatus, this, FB_FUNCTION);
+		check_database(tdbb);
+
+		try
+		{
+			ret = metadata.getFlags();
+		}
+		catch (const Exception& ex)
+		{
+			transliterateException(tdbb, ex, userStatus, "JStatement::getFlags");
+			return ret;
+		}
+	}
+	catch (const Exception& ex)
+	{
+		ex.stuffException(userStatus);
+		return ret;
+	}
+
+	successful_completion(userStatus);
+
+	return ret;
+}
+
+
 const char* JStatement::getPlan(IStatus* userStatus, FB_BOOLEAN detailed)
 {
 	const char* ret = NULL;

src/remote/client/interface.cpp

@@ -291,6 +291,7 @@ public:
 		FbMessage* inMsgBuffer, IMessageMetadata* outFormat);
 	virtual void FB_CARG setCursorName(IStatus* status, const char* name);
 	virtual void FB_CARG free(IStatus* status);
+	virtual unsigned FB_CARG getFlags(IStatus* status);
 
 public:
 	Statement(Rsr* handle, Attachment* a, unsigned aDialect)
@@ -2405,6 +2406,32 @@ unsigned Statement::getType(IStatus* status)
 }
 
 
+unsigned Statement::getFlags(IStatus* status)
+{
+	try
+	{
+		reset(status);
+
+		// Check and validate handles, etc.
+
+		CHECK_HANDLE(statement, isc_bad_req_handle);
+		Rdb* rdb = statement->rsr_rdb;
+		rem_port* port = rdb->rdb_port;
+		RefMutexGuard portGuard(*port->port_sync, FB_FUNCTION);
+
+		statement->raiseException();
+
+		return metadata.getFlags();
+	}
+	catch (const Exception& ex)
+	{
+		ex.stuffException(status);
+	}
+
+	return 0;
+}
+
+
 const char* Statement::getPlan(IStatus* status, FB_BOOLEAN detailed)
 {
 	try

src/remote/server/server.cpp

@@ -2921,14 +2921,13 @@ ISC_STATUS rem_port::execute_statement(P_OP op, P_SQLDATA* sqldata, PACKET* send
 	InternalMessageBuffer oMsgBuffer(out_blr_length, out_blr, out_msg_length, out_msg);
 	ITransaction* newTra = tra;
 
-	unsigned type = statement->rsr_iface->getType(&status_vector);
+	unsigned flags = statement->rsr_iface->getFlags(&status_vector);
 	if (!status_vector.isSuccess())
 	{
 		status_exception::raise(status_vector.get());
 	}
 
-	if ((type == isc_info_sql_stmt_select || type == isc_info_sql_stmt_select_for_upd) &&
+	if ((flags & IStatement::STATEMENT_HAS_CURSOR) && (out_msg_length == 0))
-		out_msg_length == 0)
 	{
 		if (out_blr_length)
 		{

src/yvalve/YObjects.h

@@ -325,6 +325,7 @@ public:
 		Firebird::FbMessage* in, Firebird::IMessageMetadata* out);
 	virtual void FB_CARG setCursorName(Firebird::IStatus* status, const char* name);
 	virtual void FB_CARG free(Firebird::IStatus* status);
+	virtual unsigned FB_CARG getFlags(Firebird::IStatus* status);
 
 public:
 	Firebird::Mutex cursorMutex;

src/yvalve/why.cpp

@@ -1961,14 +1961,13 @@ ISC_STATUS API_ROUTINE isc_dsql_execute2_m(ISC_STATUS* userStatus, FB_API_HANDLE
 			 Arg::Gds(isc_dsql_cursor_open_err)).raise();
 		}
 
-		unsigned type = statement->statement->getType(&status);
+		unsigned flags = statement->statement->getFlags(&status);
 		if (!status.isSuccess())
 		{
 			return status[1];
 		}
 
-		if ((type == isc_info_sql_stmt_select || type == isc_info_sql_stmt_select_for_upd) &&
+		if ((flags & IStatement::STATEMENT_HAS_CURSOR) && (outMsgLength == 0))
-			outMsgLength == 0)
 		{
 			if (outBlrLength)
 			{
@@ -3852,6 +3851,22 @@ unsigned YStatement::getType(IStatus* status)
 	return 0;
 }
 
+unsigned YStatement::getFlags(IStatus* status)
+{
+	try
+	{
+		YEntry<YStatement> entry(status, this);
+
+		return entry.next()->getFlags(status);
+	}
+	catch (const Exception& e)
+	{
+		e.stuffException(status);
+	}
+
+	return 0;
+}
+
 const char* YStatement::getPlan(IStatus* status, FB_BOOLEAN detailed)
 {
 	try