fix: correct doc drift and suppress CROSS JOIN SAWarning

- README.md: ALTER TABLE marked as supported (ADD/DROP/RENAME COLUMN)
- README.md: Rollback updated to Partial (openpyxl: yes, graph: no-op)
- docs/USAGE.md: same corrections applied to Limitations section
- compiler.py: pass from_linter=None for CROSS JOIN child dispatch
  to suppress spurious cartesian-product SAWarning

Author: yeongseon

README.md

@@ -41,10 +41,10 @@ Before writing any code, understand the dialect's capabilities and limits:
 | CTEs | ❌ |
 | UNION / UNION ALL / INTERSECT / EXCEPT | ✅ |
 | **Window functions (OVER)** | ❌ |
-| **ALTER TABLE** | ❌ |
+| **ALTER TABLE** | ✅ (ADD/DROP/RENAME COLUMN) |
 | **Foreign keys / indexes** | ❌ |
 | **Concurrent writes** | ❌ |
-| **Session.rollback()** | No-op (data persists) |
+| **Session.rollback()** | Partial (openpyxl with autocommit=False; graph: no-op) |
 
 If you need any of the ❌ features, use SQLite, PostgreSQL, or another full-featured database.
 

docs/USAGE.md

@@ -342,10 +342,10 @@ sqlalchemy-excel has some limitations due to the nature of Excel as a database:
 - **Non-correlated subqueries only**: Subqueries supported in `WHERE ... IN (SELECT ...)` for SELECT, UPDATE, and DELETE. No correlated or nested subqueries.
 - **No CTEs**: CTE queries are not supported.
 - **No window functions**: `OVER` clause raises `CompileError`.
-- **No ALTER TABLE**: Cannot modify table structure after creation.
+- **ALTER TABLE**: Supports `ADD COLUMN`, `DROP COLUMN`, and `RENAME COLUMN` via raw SQL through the driver.
 - **No foreign keys or indexes**: Excel has no concept of these.
 - **No concurrent writes**: Use a single-writer model.
-- **Rollback is a no-op**: `Session.rollback()` does nothing — the underlying driver's rollback only works at the DB-API connection level with `autocommit=False`.
+- **Rollback**: Partial support — works with the openpyxl backend when `autocommit=False` (snapshot/restore semantics). The Graph API backend treats rollback as a no-op.
 
 ## Security
 

src/sqlalchemy_excel/compiler.py

@@ -383,19 +383,21 @@ def visit_join(
             and not join.full
             and not join.isouter
         ):
+            # Intentional cartesian product -- suppress from_linter to
+            # avoid SAWarning about missing join conditions.
             left = str(
                 join.left._compiler_dispatch(
                     self,
                     asfrom=True,
-                    from_linter=from_linter,
+                    from_linter=None,
                     **kwargs,
                 )
             )
             right = str(
                 join.right._compiler_dispatch(
                     self,
                     asfrom=True,
-                    from_linter=from_linter,
+                    from_linter=None,
                     **kwargs,
                 )
             )