fix: fallback to stringarray or string if no type information provided

Signed-off-by: Ning Sun <[email protected]>

Author: sunng87

arrow-pg/src/datatypes/df.rs

@@ -68,7 +68,7 @@ where
         } else {
             // Default to TEXT for untyped parameters in extended queries
             // This allows arithmetic operations to work with implicit casting
-            Ok(Type::TEXT)
+            Ok(Type::UNKNOWN)
         }
     }
 
@@ -262,10 +262,27 @@ where
             }
             // TODO: add more advanced types (composite types, ranges, etc.)
             _ => {
-                // Default to string/text for unsupported parameter types
-                // This allows graceful degradation instead of fatal errors
+                // the client didn't provide type information and we are also
+                // unable to inference the type.
+                //
+                // In this case we retry to resolve it as String or StringArray
                 let value = portal.parameter::<String>(i, &pg_type)?;
-                deserialized_params.push(ScalarValue::Utf8(value));
+                if let Some(value) = value {
+                    if value.starts_with('{') && value.ends_with('}') {
+                        // Looks like an array
+                        let items = value.trim_matches(|c| c == '{' || c == '}' || c == ' ');
+                        let items = items.split(',').map(|s| s.trim());
+                        let scalar_values: Vec<ScalarValue> = items
+                            .map(|s| ScalarValue::Utf8(Some(s.to_string())))
+                            .collect();
+
+                        deserialized_params.push(ScalarValue::List(
+                            ScalarValue::new_list_nullable(&scalar_values, &DataType::Utf8),
+                        ));
+                    } else {
+                        deserialized_params.push(ScalarValue::Utf8(Some(value)));
+                    }
+                }
             }
         }
     }

datafusion-postgres/src/handlers.rs

@@ -667,6 +667,7 @@ impl ExtendedQueryHandler for DfSessionService {
         let param_types = plan
             .get_parameter_types()
             .map_err(|e| PgWireError::ApiError(Box::new(e)))?;
+
         let param_values = df::deserialize_parameters(portal, &ordered_param_types(&param_types))?; // Fixed: Use &param_types
 
         let plan = plan
@@ -697,12 +698,10 @@ impl ExtendedQueryHandler for DfSessionService {
                 })?
                 .map_err(|e| PgWireError::ApiError(Box::new(e)))?
             } else {
-                match self.session_context.execute_logical_plan(optimised).await {
-                    Ok(df) => df,
-                    Err(e) => {
-                        return Err(PgWireError::ApiError(Box::new(e)));
-                    }
-                }
+                self.session_context
+                    .execute_logical_plan(optimised)
+                    .await
+                    .map_err(|e| PgWireError::ApiError(Box::new(e)))?
             }
         };
         let resp = df::encode_dataframe(dataframe, &portal.result_column_format).await?;