diff --git a/demo.py b/demo.py
index d074658..228c38c 100644
--- a/demo.py
+++ b/demo.py
@@ -29,8 +29,8 @@ class UserModel(BaseDBModel):
     class Meta:
         """Override the default options for the UserModel."""
 
-        create_pk: bool = False  # Disable auto-increment ID
-        primary_key: str = "slug"  # Use 'slug' as the primary key
+        create_pk: bool = True  # Disable auto-increment ID
+        # primary_key: str = "slug"  # Use 'slug' as the PK  # noqa: ERA001
         table_name: str = "users"  # Explicitly define the table name
 
 
@@ -41,7 +41,7 @@ def main() -> None:
         level=logging.DEBUG, format="%(levelname)-8s%(message)s"
     )
 
-    db = SqliterDB(memory=True, auto_commit=True, debug=True)
+    db = SqliterDB("poop.db", memory=False, auto_commit=True, debug=True)
     with db:
         db.create_table(UserModel)  # Create the users table
         user1 = UserModel(
diff --git a/sqliter/query/query.py b/sqliter/query/query.py
index 704c30d..ff6b2b3 100644
--- a/sqliter/query/query.py
+++ b/sqliter/query/query.py
@@ -146,6 +146,15 @@ def fields(self, fields: Optional[list[str]] = None) -> QueryBuilder:
         """
         if fields:
             self._fields = fields
+            # Ensure the primary key is included and placed first if create_pk
+            # is True
+            if self.model_class.should_create_pk():
+                primary_key = self.model_class.get_primary_key()
+                if primary_key in self._fields:
+                    self._fields.remove(
+                        primary_key
+                    )  # Remove if it's already there
+                self._fields.insert(0, primary_key)  # Add it at the beginning
             self._validate_fields()
         return self
 
diff --git a/sqliter/sqliter.py b/sqliter/sqliter.py
index 7e2a392..bf274da 100644
--- a/sqliter/sqliter.py
+++ b/sqliter/sqliter.py
@@ -492,6 +492,14 @@ def select(
         Returns:
             A QueryBuilder instance for further query construction.
         """
+        # Ensure the primary key is included and placed first
+        if model_class.should_create_pk():
+            primary_key = model_class.get_primary_key()
+            if fields:
+                if primary_key in fields:
+                    fields.remove(primary_key)
+                fields.insert(0, primary_key)
+
         query_builder = QueryBuilder(self, model_class, fields)
 
         # If exclude is provided, apply the exclude method