More fixes and additions for forms. We are also haunted by detached sessions constantly.

crudkit/backend.py

@@ -74,18 +74,32 @@ def apply_pagination(sel: Select, backend: BackendInfo, *, page: int, per_page:
     per_page = max(1, int(per_page))
     offset = (page - 1) * per_page
 
-    if backend.requires_order_by_for_offset and not sel._order_by_clauses:
-        if default_order_by is None:
-            sel = sel.order_by(text("1"))
-        else:
-            sel = sel.order_by(default_order_by)
+    if backend.requires_order_by_for_offset:
+        # Avoid private attribute if possible:
+        has_order = bool(getattr(sel, "_order_by_clauses", ()))  # fallback for SA < 2.0.30
+        try:
+            has_order = has_order or bool(sel.get_order_by())
+        except Exception:
+            pass
+
+        if not has_order:
+            if default_order_by is not None:
+                sel = sel.order_by(default_order_by)
+            else:
+                # Try to find a primary key from the FROMs; fall back to a harmless literal.
+                try:
+                    first_from = sel.get_final_froms()[0]
+                    pk = next(iter(first_from.primary_key.columns))
+                    sel = sel.order_by(pk)
+                except Exception:
+                    sel = sel.order_by(text("1"))
 
     return sel.limit(per_page).offset(offset)
 
 @contextmanager
 def maybe_identify_insert(session: Session, table, backend: BackendInfo):
     """
-    For MSSQL tables with IDENTIFY PK when you need to insert explicit IDs.
+    For MSSQL tables with IDENTITY PK when you need to insert explicit IDs.
     No-op elsewhere.
     """
     if not backend.is_mssql:
@@ -93,7 +107,7 @@ def maybe_identify_insert(session: Session, table, backend: BackendInfo):
         return
 
     full_name = f"{table.schema}.{table.name}" if table.schema else table.name
-    session.execute(text(f"SET IDENTIFY_INSERT {full_name} ON"))
+    session.execute(text(f"SET IDENTITY_INSERT {full_name} ON"))
     try:
         yield
     finally:
@@ -101,7 +115,7 @@ def maybe_identify_insert(session: Session, table, backend: BackendInfo):
 
 def chunked_in(column, values: Iterable, backend: BackendInfo, chunk_size: Optional[int] = None) -> ClauseElement:
     """
-    Build a safe large IN() filter respecting bund param limits.
+    Build a safe large IN() filter respecting bind param limits.
     Returns a disjunction of chunked IN clauses if needed.
     """
     vals = list(values)
@@ -120,3 +134,12 @@ def chunked_in(column, values: Iterable, backend: BackendInfo, chunk_size: Optio
     for p in parts[1:]:
         expr = expr | p
     return expr
+
+def sql_trim(expr, backend: BackendInfo):
+    """
+    Portable TRIM. SQL Server before compat level 140 lacks TRIM().
+    Emit LTRIM(RTRIM(...)) there; use TRIM elsewhere
+    """
+    if backend.is_mssql:
+        return func.ltrim(func.rtrim(expr))
+    return func.trim(expr)