#pragma once #include #include #include #include namespace DB { class StorageView final : public shared_ptr_helper, public IStorage { friend struct shared_ptr_helper; public: std::string getName() const override { return "View"; } bool isView() const override { return true; } /// It is passed inside the query and solved at its level. bool supportsSampling() const override { return true; } bool supportsFinal() const override { return true; } Pipe read( const Names & column_names, const StorageMetadataPtr & /*metadata_snapshot*/, SelectQueryInfo & query_info, ContextPtr context, QueryProcessingStage::Enum processed_stage, size_t max_block_size, unsigned num_streams) override; void read( QueryPlan & query_plan, const Names & column_names, const StorageMetadataPtr & metadata_snapshot, SelectQueryInfo & query_info, ContextPtr context, QueryProcessingStage::Enum processed_stage, size_t max_block_size, unsigned num_streams) override; void replaceWithSubquery(ASTSelectQuery & select_query, ASTPtr & view_name, const StorageMetadataPtr & metadata_snapshot) const { replaceWithSubquery(select_query, metadata_snapshot->getSelectQuery().inner_query->clone(), view_name); } static void replaceWithSubquery(ASTSelectQuery & outer_query, ASTPtr view_query, ASTPtr & view_name); static ASTPtr restoreViewName(ASTSelectQuery & select_query, const ASTPtr & view_name); protected: StorageView(const StorageID & table_id_, const ASTCreateQuery & query, const ColumnsDescription & columns_, const String & comment); }; }