feat(pdo): statement-level get/set-attribute via polymorphic dispatch

CHANGELOG.md

@@ -14,6 +14,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `pdo/close-cursor` - wrap `PDOStatement::closeCursor`; frees the cursor so the statement can be re-executed ([#9]).
 - `pdo/fetch-object` - wrap `PDOStatement::fetchObject`; returns the next row as an object (`stdClass` or a named class), or `nil` when exhausted ([#11]).
 
+### Changed
+
+- `pdo/get-attribute` / `pdo/set-attribute` now dispatch on the handle: pass a connection (as before) or a statement to reach `PDOStatement::getAttribute` / `setAttribute` ([#12]).
+
 ## [0.1.0] - 2026-05-13
 
 ### Changed

README.md

@@ -78,7 +78,7 @@ All functions live in the `phel.pdo` namespace.
 | `last-insert-id` | `(last-insert-id conn)` | ID of the last inserted row. |
 | `begin` / `commit` / `rollback` | `(begin conn)` … | Transaction control. |
 | `in-transaction` | `(in-transaction conn)` | `true` if a transaction is active. |
-| `get-attribute` / `set-attribute` | `(get-attribute conn attr)` / `(set-attribute conn attr value)` | PDO attribute access. |
+| `get-attribute` / `set-attribute` | `(get-attribute handle attr)` / `(set-attribute handle attr value)` | PDO attribute access; `handle` is a connection or a statement. |
 | `get-available-drivers` | `(get-available-drivers conn)` | Vector of installed PDO drivers. |
 | `error-code` | `(error-code conn)` | SQLSTATE of the last operation. |
 | `error-info` | `(error-info conn)` | `[sqlstate driver-code driver-message]`. |

src/pdo.phel

@@ -2,15 +2,22 @@
 
 (defstruct connection [pdo])
 
+(declare statement?)
+
+(defn- attr-target
+  "The PDO handle behind a connection or statement struct."
+  [handle]
+  (if (statement? handle) (handle :stmt) (handle :pdo)))
+
 (defn ^bool set-attribute
-  "Set an attribute"
-  [conn attribute value]
-  (php/-> (conn :pdo) (setAttribute attribute value)))
+  "Set an attribute on a connection or statement"
+  [handle attribute value]
+  (php/-> (attr-target handle) (setAttribute attribute value)))
 
 (defn get-attribute
-  "Retrieve a database connection attribute"
-  [conn attribute]
-  (php/-> (conn :pdo) (getAttribute attribute)))
+  "Retrieve an attribute from a connection or statement"
+  [handle attribute]
+  (php/-> (attr-target handle) (getAttribute attribute)))
 
 (defn connect
   "Connect database and return connection object.

src/pdo/statement.phel

@@ -79,9 +79,7 @@
 ;; PDOStatement::bindColumn      — Bind a column to a PHP variable
 ;; PDOStatement::errorCode       — Fetch the SQLSTATE associated with the last operation on the statement handle
 ;; PDOStatement::errorInfo       — Fetch extended error information associated with the last operation on the statement handle
-;; PDOStatement::getAttribute    — Retrieve a statement attribute
 ;; PDOStatement::getColumnMeta   — Returns metadata for a column in a result set
 ;; PDOStatement::getIterator     — Gets result set iterator
 ;; PDOStatement::nextRowset      — Advances to the next rowset in a multi-rowset statement handle
-;; PDOStatement::setAttribute    — Set a statement attribute
 ;; PDOStatement::setFetchMode    — Set the default fetch mode for this statement

tests/pdo_test.phel

@@ -183,6 +183,28 @@
         stmt (pdo/execute stmt {:id 1})]
     (is (= "phel" (pdo/fetch-column stmt)))))
 
+(deftest set-attribute-dispatches-to-statement
+  (seed-t1 *conn*)
+  ;; SQLite rejects statement attributes; depending on the driver build this is
+  ;; either a false return or a PDOException - both prove the call reached the statement.
+  (let [stmt    (pdo/prepare *conn* "select * from t1")
+        outcome (try
+                  (pdo/set-attribute stmt \PDO/ATTR_CURSOR \PDO/CURSOR_FWDONLY)
+                  (catch \PDOException _e :unsupported))]
+    (is (or (= false outcome) (= :unsupported outcome)))))
+
+(deftest get-attribute-dispatches-to-statement
+  (seed-t1 *conn*)
+  (testing "connection branch still returns a value"
+           (is (= \PDO/ERRMODE_EXCEPTION (pdo/get-attribute *conn* \PDO/ATTR_ERRMODE))))
+  (testing "statement branch routes to the PDOStatement (SQLite reports unsupported)"
+           (let [stmt  (pdo/prepare *conn* "select * from t1")
+                 threw (try
+                         (pdo/get-attribute stmt \PDO/ATTR_CURSOR)
+                         false
+                         (catch \PDOException _e true))]
+             (is (= true threw)))))
+
 (deftest debug-dump-params-emits-sql-header
   (seed-t1 *conn*)
   (let [stmt  (pdo/prepare *conn* "select * from t1 where name = :name")