YQL-20307: Support inline subqueries

- Alter grammar to support inline subqueries.
- Support inline subqueries in `sql/v1` (translator).
- Introduce `sql/v1/proto_ast/parse_tree.h` for reusable parse tree predicates.
- Support inline subqueries in `sql/v1/format`.
- Support inline subqueries in `sql/v1/complete`.
- Add some SQL-tests.
- Pass all tests.
commit_hash:075b2240778d071e1c7542f912d3cc83019ef849

1 files changed, 4 insertions, 0 deletions

diff --git a/yql/essentials/sql/v1/select.cpp b/yql/essentials/sql/v1/select.cpp
index c6ba387e7bd..41689db592c 100644
--- a/yql/essentials/sql/v1/select.cpp
+++ b/yql/essentials/sql/v1/select.cpp
@@ -662,6 +662,10 @@ TNodePtr BuildSubqueryRef(TNodePtr subquery, const TString& alias, int tupleInde
     return new TSubqueryRefNode(std::move(subquery), alias, tupleIndex);
 }
 
+bool IsSubqueryRef(const TSourcePtr& source) {
+    return dynamic_cast<const TSubqueryRefNode*>(source.Get()) != nullptr;
+}
+
 class TInvalidSubqueryRefNode: public ISource {
 public:
     TInvalidSubqueryRefNode(TPosition pos)