From 08dd6a8c5e42ea164ac33e8b321f395f8ee032fb Mon Sep 17 00:00:00 2001
From: David M <656337+davidov541@users.noreply.github.com>
Date: Thu, 26 Jan 2023 13:46:36 -0600
Subject: [PATCH 1/4] Fixing issue where table does not exist doesn't return
 the right exception.

---
 src/snowflake/sqlalchemy/snowdialect.py |  8 +++++++-
 tests/test_core.py                      | 14 +++++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/snowflake/sqlalchemy/snowdialect.py b/src/snowflake/sqlalchemy/snowdialect.py
index 5003f286..1cc9a0a3 100644
--- a/src/snowflake/sqlalchemy/snowdialect.py
+++ b/src/snowflake/sqlalchemy/snowdialect.py
@@ -637,6 +637,9 @@ def _get_table_columns(self, connection, table_name, schema=None, **kw):
 
             type_instance = col_type(**col_type_kw)
 
+            if table_name not in schema_primary_keys:
+                raise sa_exc.NoSuchTableError()
+
             current_table_pks = schema_primary_keys.get(table_name)
 
             ans.append(
@@ -669,7 +672,10 @@ def get_columns(self, connection, table_name, schema=None, **kw):
         if schema_columns is None:
             # Too many results, fall back to only query about single table
             return self._get_table_columns(connection, table_name, schema, **kw)
-        return schema_columns[self.normalize_name(table_name)]
+        normalized_table_name = self.normalize_name(table_name)
+        if normalized_table_name not in schema_columns:
+            raise sa_exc.NoSuchTableError()
+        return schema_columns[normalized_table_name]
 
     @reflection.cache
     def get_table_names(self, connection, schema=None, **kw):
diff --git a/tests/test_core.py b/tests/test_core.py
index 68a2a12e..353ddefc 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -32,7 +32,7 @@
     inspect,
     text,
 )
-from sqlalchemy.exc import DBAPIError
+from sqlalchemy.exc import DBAPIError, NoSuchTableError
 from sqlalchemy.pool import NullPool
 from sqlalchemy.sql import and_, not_, or_, select
 
@@ -417,6 +417,18 @@ def test_insert_tables(engine_testaccount):
             users.drop(engine_testaccount)
 
 
+def test_table_does_not_exist(engine_testaccount):
+    """
+    Tests Correct Exception Thrown When Table Does Not Exist
+    """
+    with engine_testaccount.connect() as conn:
+        meta = MetaData()
+        with pytest.raises(NoSuchTableError):
+            Table(
+                "does_not_exist", meta, autoload=True, autoload_with=engine_testaccount
+            )
+
+
 @pytest.mark.skip(
     """
 Reflection is not implemented yet.

From fb39add6d906e25edb04352e6931ef2649d01904 Mon Sep 17 00:00:00 2001
From: David M <656337+davidov541@users.noreply.github.com>
Date: Thu, 16 Feb 2023 12:54:34 -0600
Subject: [PATCH 2/4] Adding new entry in release notes for the changes we've
 made.

---
 DESCRIPTION.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/DESCRIPTION.md b/DESCRIPTION.md
index d5778699..4f475218 100644
--- a/DESCRIPTION.md
+++ b/DESCRIPTION.md
@@ -9,6 +9,10 @@ Source code is also available at:
 
 # Release Notes
 
+- v1.4.7(Feb 16, 2023)
+
+- `SnowflakeDialect.get_columns` now throws a `NoSuchTableError` exception when the specified table doesn't exist, instead of the more vague `KeyError`.
+
 - v1.4.6(Feb 8, 2023)
 
 - Bumped snowflake-connector-python dependency to newest version which supports Python 3.11.

From 858af66f36e080e9e4658c1624dbb9a420b47786 Mon Sep 17 00:00:00 2001
From: David M <656337+davidov541@users.noreply.github.com>
Date: Fri, 10 Mar 2023 17:52:23 -0600
Subject: [PATCH 3/4] Switching mechanism for checking for no such table.

---
 src/snowflake/sqlalchemy/snowdialect.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/snowflake/sqlalchemy/snowdialect.py b/src/snowflake/sqlalchemy/snowdialect.py
index 1cc9a0a3..d96a3b09 100644
--- a/src/snowflake/sqlalchemy/snowdialect.py
+++ b/src/snowflake/sqlalchemy/snowdialect.py
@@ -637,9 +637,6 @@ def _get_table_columns(self, connection, table_name, schema=None, **kw):
 
             type_instance = col_type(**col_type_kw)
 
-            if table_name not in schema_primary_keys:
-                raise sa_exc.NoSuchTableError()
-
             current_table_pks = schema_primary_keys.get(table_name)
 
             ans.append(
@@ -658,6 +655,10 @@ def _get_table_columns(self, connection, table_name, schema=None, **kw):
                     else False,
                 }
             )
+
+        # If we didn't find any columns for the table, the table doesn't exist.
+        if len(ans) == 0:
+            raise sa_exc.NoSuchTableError()
         return ans
 
     def get_columns(self, connection, table_name, schema=None, **kw):

From 59a4b37cf18ef51ab4799e85308158ee594b95a8 Mon Sep 17 00:00:00 2001
From: David M <656337+davidov541@users.noreply.github.com>
Date: Tue, 14 Mar 2023 12:05:39 -0500
Subject: [PATCH 4/4] Removing connection for test that is not really needed.

Co-authored-by: Adam Ling <adam.ling@snowflake.com>
---
 tests/test_core.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/tests/test_core.py b/tests/test_core.py
index ab334c9e..48a0d900 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -410,12 +410,9 @@ def test_table_does_not_exist(engine_testaccount):
     """
     Tests Correct Exception Thrown When Table Does Not Exist
     """
-    with engine_testaccount.connect() as conn:
-        meta = MetaData()
-        with pytest.raises(NoSuchTableError):
-            Table(
-                "does_not_exist", meta, autoload=True, autoload_with=engine_testaccount
-            )
+    meta = MetaData()
+    with pytest.raises(NoSuchTableError):
+        Table("does_not_exist", meta, autoload=True, autoload_with=engine_testaccount)
 
 
 @pytest.mark.skip(