Function dsqlPassCursorReference

src/dsql/StmtNodes.cpp:10187–10266

Turn a cursor reference into a record selection expression.

// Turn a cursor reference into a record selection expression.
static RseNode* dsqlPassCursorReference(DsqlCompilerScratch* dsqlScratch, const MetaName& cursor,
	RelationSourceNode* relation_name)
{
	DEV_BLKCHK(dsqlScratch, dsql_type_req);

	thread_db* tdbb = JRD_get_thread_data();
	MemoryPool& pool = *tdbb->getDefaultPool();

	// Lookup parent dsqlScratch

	const auto* const symbol = dsqlScratch->getAttachment()->dbb_cursors.get(cursor.c_str());

	if (!symbol)
	{
		// cursor is not found
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-504) <<
				  Arg::Gds(isc_dsql_cursor_err) <<
				  Arg::Gds(isc_dsql_cursor_not_found) << cursor);
	}

	auto parent = *symbol;

	// Verify that the cursor is appropriate and updatable

	dsql_par* source = dsqlFindDbKey(parent->getDsqlStatement(), relation_name);
	dsql_par* rv_source = dsqlFindRecordVersion(parent->getDsqlStatement(), relation_name);

	if (!source || !rv_source)
	{
		// cursor is not updatable
		ERRD_post(Arg::Gds(isc_sqlerr) << Arg::Num(-510) <<
				  Arg::Gds(isc_dsql_cursor_update_err) << cursor);
	}

	const auto statement = static_cast<DsqlDmlStatement*>(dsqlScratch->getDsqlStatement());

	statement->setParentRequest(parent);
	statement->setParentDbKey(source);
	statement->setParentRecVersion(rv_source);
	parent->cursors.add(statement);

	// Build record selection expression

	RseNode* rse = FB_NEW_POOL(pool) RseNode(pool);
	rse->dsqlStreams = FB_NEW_POOL(pool) RecSourceListNode(pool, 1);
	RelationSourceNode* relation_node = nodeAs<RelationSourceNode>(PASS1_relation(dsqlScratch, relation_name));
	rse->dsqlStreams->items[0] = relation_node;

	RecordKeyNode* dbKeyNode = FB_NEW_POOL(pool) RecordKeyNode(pool, blr_dbkey);
	dbKeyNode->dsqlRelation = relation_node;

	dsql_par* parameter = MAKE_parameter(statement->getSendMsg(), false, false, 0, NULL);
	statement->setDbKey(parameter);

	ParameterNode* paramNode = FB_NEW_POOL(pool) ParameterNode(pool);
	paramNode->dsqlParameterIndex = parameter->par_index;
	paramNode->dsqlParameter = parameter;
	parameter->par_desc = source->par_desc;