From 0970a4a76cd060dd3695685039ad926c484103c9 Mon Sep 17 00:00:00 2001
From: Eric Masseran <eric.masseran@gmail.com>
Date: Fri, 16 Jul 2021 12:02:42 +0200
Subject: [PATCH] Do not check language support

---
 lib/sqlalchemy/dialects/postgresql/base.py |  1 -
 lib/sqlalchemy/dialects/sqlite/base.py     |  1 -
 lib/sqlalchemy/engine/default.py           |  1 -
 lib/sqlalchemy/sql/compiler.py             |  6 ------
 test/sql/test_cte.py                       | 21 ---------------------
 5 files changed, 30 deletions(-)

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index baa0efe4b2..4c654a643b 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -3091,7 +3091,6 @@ class PGDialect(default.DefaultDialect):
 
     supports_comments = True
     supports_default_values = True
-    supports_nesting_cte = True
 
     supports_default_metavalue = True
 
diff --git a/lib/sqlalchemy/dialects/sqlite/base.py b/lib/sqlalchemy/dialects/sqlite/base.py
index 4d0cb56ade..66a556ae0d 100644
--- a/lib/sqlalchemy/dialects/sqlite/base.py
+++ b/lib/sqlalchemy/dialects/sqlite/base.py
@@ -1807,7 +1807,6 @@ class SQLiteDialect(default.DefaultDialect):
     supports_multivalues_insert = True
     tuple_in_values = True
     supports_statement_cache = True
-    supports_nesting_cte = True
 
     default_paramstyle = "qmark"
     execution_ctx_cls = SQLiteExecutionContext
diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index 8cdde558b6..7b3fa091fd 100644
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -81,7 +81,6 @@ class DefaultDialect(interfaces.Dialect):
     insert_executemany_returning = False
 
     cte_follows_insert = False
-    supports_nesting_cte = False
 
     supports_native_enum = False
     supports_native_boolean = False
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index e0c1028190..f5079c74a4 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -3361,12 +3361,6 @@ class SQLCompiler(Compiled):
                 if not cte.nesting and self.level_by_ctes[cte] == nesting_level
             }
 
-            if ctes and not self.dialect.supports_nesting_cte:
-                raise exc.CompileError(
-                    "Nesting CTE is not supported by this "
-                    "dialect's statement compiler."
-                )
-
         ctes_recursive = any([cte.recursive for cte in ctes])
 
         if self.positional:
diff --git a/test/sql/test_cte.py b/test/sql/test_cte.py
index 04d8a999c0..72e3f506e8 100644
--- a/test/sql/test_cte.py
+++ b/test/sql/test_cte.py
@@ -1,5 +1,4 @@
 import functools
-import pytest
 from sqlalchemy import delete
 from sqlalchemy import testing
 from sqlalchemy import text
@@ -1570,26 +1569,6 @@ class NestingCTETest(fixtures.TestBase, AssertsCompiledSQL):
             "SELECT cte.outer_cte FROM cte",
         )
 
-    @pytest.mark.parametrize(
-        "dialect",
-        [mysql],
-    )
-    def test_nesting_cte_unsupported_backend_raise(self, dialect):
-        stmt = select(
-            [
-                select(
-                    [select([literal(1).label("one")]).cte("t2", nesting=True)]
-                ).cte("t")
-            ]
-        )
-
-        assert_raises_message(
-            CompileError,
-            "Nesting CTE is not supported by this "
-            "dialect's statement compiler.",
-            functools.partial(stmt.compile, dialect=dialect.dialect()),
-        )
-
     def test_select_from_insert_cte_with_nesting(self):
         products = table("products", column("id"), column("price"))
 
-- 
2.47.3