From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 2 Dec 2024 23:59:19 +0000 (-0500)
Subject: use VARCHAR for CLOB outputtypehandler
X-Git-Tag: rel_2_0_37~30
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=32652c1980bb10c46ec09971a8c0d7786c117889;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

use VARCHAR for CLOB outputtypehandler

Fixed issue in oracledb / cx_oracle dialects where output type handlers for
``CLOB`` were being routed to ``NVARCHAR`` rather than ``VARCHAR``, causing
a double conversion to take place.

Fixes: #12150
Change-Id: I9f55e9bc595997b873c831b0422f5af10dcc15ef
(cherry picked from commit 5ded16fae8abfc31d43430cb25757fb434c37ba2)
---

diff --git a/doc/build/changelog/unreleased_20/12150.rst b/doc/build/changelog/unreleased_20/12150.rst
new file mode 100644
index 0000000000..a40e4623f2
--- /dev/null
+++ b/doc/build/changelog/unreleased_20/12150.rst
@@ -0,0 +1,8 @@
+.. change::
+    :tags: bug, oracle
+    :tickets: 12150
+
+    Fixed issue in oracledb / cx_oracle dialects where output type handlers for
+    ``CLOB`` were being routed to ``NVARCHAR`` rather than ``VARCHAR``, causing
+    a double conversion to take place.
+
diff --git a/lib/sqlalchemy/dialects/oracle/cx_oracle.py b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
index 9b66d7ea78..6a2588883b 100644
--- a/lib/sqlalchemy/dialects/oracle/cx_oracle.py
+++ b/lib/sqlalchemy/dialects/oracle/cx_oracle.py
@@ -1353,8 +1353,13 @@ class OracleDialect_cx_oracle(OracleDialect):
                 cx_Oracle.CLOB,
                 cx_Oracle.NCLOB,
             ):
+                typ = (
+                    cx_Oracle.DB_TYPE_VARCHAR
+                    if default_type is cx_Oracle.CLOB
+                    else cx_Oracle.DB_TYPE_NVARCHAR
+                )
                 return cursor.var(
-                    cx_Oracle.DB_TYPE_NVARCHAR,
+                    typ,
                     _CX_ORACLE_MAGIC_LOB_SIZE,
                     cursor.arraysize,
                     **dialect._cursor_var_unicode_kwargs,