fix: refine parameter style handling and execution style checks

Author: cofin

sqlspec/adapters/duckdb/core.py

@@ -145,7 +145,7 @@ def build_profile() -> "DriverParameterProfile":
         default_style=ParameterStyle.QMARK,
         supported_styles={ParameterStyle.QMARK, ParameterStyle.NUMERIC, ParameterStyle.NAMED_DOLLAR},
         default_execution_style=ParameterStyle.QMARK,
-        supported_execution_styles={ParameterStyle.QMARK, ParameterStyle.NUMERIC, ParameterStyle.NAMED_DOLLAR},
+        supported_execution_styles={ParameterStyle.QMARK, ParameterStyle.NUMERIC},
         has_native_list_expansion=True,
         preserve_parameter_format=True,
         needs_static_script_compilation=False,

sqlspec/core/parameters/_alignment.py

@@ -106,7 +106,17 @@ def collect_null_parameter_ordinals(parameters: Any, profile: "ParameterProfile"
 
 def _collect_expected_identifiers(parameter_profile: "ParameterProfile") -> "set[tuple[str, int | str]]":
     identifiers: set[tuple[str, int | str]] = set()
-    for parameter in parameter_profile.parameters:
+    parameters = parameter_profile.parameters
+    if not parameters:
+        return identifiers
+
+    # Check if we have mixed styles - if so, use ordinal-based counting for positional styles
+    styles = {p.style for p in parameters}
+    has_mixed_positional_styles = len(styles) > 1 and any(
+        s in styles for s in {ParameterStyle.QMARK, ParameterStyle.POSITIONAL_PYFORMAT}
+    )
+
+    for parameter in parameters:
         style = parameter.style
         name = parameter.name
         if style in {
@@ -117,7 +127,10 @@ def _collect_expected_identifiers(parameter_profile: "ParameterProfile") -> "set
         }:
             identifiers.add(("named", name or f"param_{parameter.ordinal}"))
         elif style in {ParameterStyle.NUMERIC, ParameterStyle.POSITIONAL_COLON}:
-            if name and name.isdigit():
+            # When mixed with ordinal styles (like QMARK), use ordinal instead of explicit index
+            if has_mixed_positional_styles:
+                identifiers.add(("index", parameter.ordinal))
+            elif name and name.isdigit():
                 identifiers.add(("index", int(name) - 1))
             else:
                 identifiers.add(("index", parameter.ordinal))

sqlspec/core/parameters/_converter.py

@@ -274,7 +274,7 @@ def _preserve_original_format(
             return tuple(param_values)
         return tuple(param_values)
 
-    def _convert_parameter_format(
+    def _convert_parameter_format(  # noqa: C901
         self,
         parameters: "ParameterPayload",
         param_info: "list[ParameterInfo]",
@@ -327,6 +327,9 @@ def _convert_parameter_format(
             ParameterStyle.NAMED_DOLLAR,
             ParameterStyle.NAMED_PYFORMAT,
         }
+        # POSITIONAL_COLON is a special case that always requires dict output
+        if target_style == ParameterStyle.POSITIONAL_COLON:
+            return self._convert_to_positional_colon_format(parameters, param_info)
 
         if is_named_style:
             if isinstance(parameters, Mapping):

sqlspec/core/parameters/_processor.py

@@ -461,13 +461,6 @@ def _needs_execution_placeholder_conversion(
         ):
             return False
 
-        if (
-            config.supported_execution_parameter_styles is not None
-            and len(config.supported_execution_parameter_styles) > 1
-            and all(style in config.supported_execution_parameter_styles for style in current_styles)
-        ):
-            return False
-
         if len(current_styles) > 1:
             return True