From c8791fec4be9d463cec35eff1ee51777fdae2b82 Mon Sep 17 00:00:00 2001
From: Jano Valaska <jano@ccnbikes.com>
Date: Fri, 25 Feb 2022 00:31:04 +0100
Subject: [PATCH] table invalidation condition enhanced (#213)

---
 cachalot/monkey_patch.py | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/cachalot/monkey_patch.py b/cachalot/monkey_patch.py
index f152864..60cb9f6 100644
--- a/cachalot/monkey_patch.py
+++ b/cachalot/monkey_patch.py
@@ -1,3 +1,4 @@
+import re
 from collections.abc import Iterable
 from functools import wraps
 from time import time
@@ -21,6 +22,13 @@ from .utils import (
 
 WRITE_COMPILERS = (SQLInsertCompiler, SQLUpdateCompiler, SQLDeleteCompiler)
 
+SQL_DATA_CHANGE_RE = re.compile(
+    '|'.join([
+        fr'(\W|\A){re.escape(keyword)}(\W|\Z)'
+        for keyword in ['update', 'insert', 'delete', 'alter', 'create', 'drop']
+    ]),
+    flags=re.IGNORECASE,
+)
 
 def _unset_raw_connection(original):
     def inner(compiler, *args, **kwargs):
@@ -133,9 +141,7 @@ def _patch_cursor():
                     if isinstance(sql, bytes):
                         sql = sql.decode('utf-8')
                     sql = sql.lower()
-                    if 'update' in sql or 'insert' in sql or 'delete' in sql \
-                            or 'alter' in sql or 'create' in sql \
-                            or 'drop' in sql:
+                    if SQL_DATA_CHANGE_RE.search(sql):
                         tables = filter_cachable(
                             _get_tables_from_sql(connection, sql))
                         if tables: