Merging upstream version 20.3.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 19 insertions, 20 deletions

diff --git a/sqlglot/optimizer/scope.py b/sqlglot/optimizer/scope.py
index b7e527e..d34857d 100644
--- a/sqlglot/optimizer/scope.py
+++ b/sqlglot/optimizer/scope.py
@@ -37,6 +37,7 @@ class Scope:
             For example:
                 SELECT c FROM x LATERAL VIEW EXPLODE (a) AS c;
             The LATERAL VIEW EXPLODE gets x as a source.
+        cte_sources (dict[str, Scope]): Sources from CTES
         outer_column_list (list[str]): If this is a derived table or CTE, and the outer query
             defines a column list of it's alias of this scope, this is that list of columns.
             For example:
@@ -61,11 +62,14 @@ class Scope:
         parent=None,
         scope_type=ScopeType.ROOT,
         lateral_sources=None,
+        cte_sources=None,
     ):
         self.expression = expression
         self.sources = sources or {}
-        self.lateral_sources = lateral_sources.copy() if lateral_sources else {}
+        self.lateral_sources = lateral_sources or {}
+        self.cte_sources = cte_sources or {}
         self.sources.update(self.lateral_sources)
+        self.sources.update(self.cte_sources)
         self.outer_column_list = outer_column_list or []
         self.parent = parent
         self.scope_type = scope_type
@@ -92,13 +96,17 @@ class Scope:
         self._pivots = None
         self._references = None
 
-    def branch(self, expression, scope_type, chain_sources=None, **kwargs):
+    def branch(
+        self, expression, scope_type, sources=None, cte_sources=None, lateral_sources=None, **kwargs
+    ):
         """Branch from the current scope to a new, inner scope"""
         return Scope(
             expression=expression.unnest(),
-            sources={**self.cte_sources, **(chain_sources or {})},
+            sources=sources.copy() if sources else None,
             parent=self,
             scope_type=scope_type,
+            cte_sources={**self.cte_sources, **(cte_sources or {})},
+            lateral_sources=lateral_sources.copy() if lateral_sources else None,
             **kwargs,
         )
 
@@ -306,20 +314,6 @@ class Scope:
         return self._references
 
     @property
-    def cte_sources(self):
-        """
-        Sources that are CTEs.
-
-        Returns:
-            dict[str, Scope]: Mapping of source alias to Scope
-        """
-        return {
-            alias: scope
-            for alias, scope in self.sources.items()
-            if isinstance(scope, Scope) and scope.is_cte
-        }
-
-    @property
     def external_columns(self):
         """
         Columns that appear to reference sources in outer scopes.
@@ -515,7 +509,10 @@ def _traverse_scope(scope):
     elif isinstance(scope.expression, exp.Union):
         yield from _traverse_union(scope)
     elif isinstance(scope.expression, exp.Subquery):
-        yield from _traverse_subqueries(scope)
+        if scope.is_root:
+            yield from _traverse_select(scope)
+        else:
+            yield from _traverse_subqueries(scope)
     elif isinstance(scope.expression, exp.Table):
         yield from _traverse_tables(scope)
     elif isinstance(scope.expression, exp.UDTF):
@@ -572,7 +569,7 @@ def _traverse_ctes(scope):
         for child_scope in _traverse_scope(
             scope.branch(
                 cte.this,
-                chain_sources=sources,
+                cte_sources=sources,
                 outer_column_list=cte.alias_column_names,
                 scope_type=ScopeType.CTE,
             )
@@ -584,12 +581,14 @@ def _traverse_ctes(scope):
 
             if recursive_scope:
                 child_scope.add_source(alias, recursive_scope)
+                child_scope.cte_sources[alias] = recursive_scope
 
         # append the final child_scope yielded
         if child_scope:
             scope.cte_scopes.append(child_scope)
 
     scope.sources.update(sources)
+    scope.cte_sources.update(sources)
 
 
 def _is_derived_table(expression: exp.Subquery) -> bool:
@@ -725,7 +724,7 @@ def _traverse_ddl(scope):
     yield from _traverse_ctes(scope)
 
     query_scope = scope.branch(
-        scope.expression.expression, scope_type=ScopeType.DERIVED_TABLE, chain_sources=scope.sources
+        scope.expression.expression, scope_type=ScopeType.DERIVED_TABLE, sources=scope.sources
     )
     query_scope._collect()
     query_scope._ctes = scope.ctes + query_scope._ctes