Add support for MAX_IDENTIFIER_LENGTH value of the database

Author: sharadraju

doc/src/api_manual/connection.rst

@@ -191,6 +191,20 @@ The properties of a *Connection* object are listed below.
     associated with the connection. It returns the same value as the SQL expression
     ``sys_context('userenv', 'instance_name')``.
 
+.. attribute:: connection.maxIdentifierLength
+
+    .. versionadded:: 6.8
+
+    This read-only attribute specifies the maximum database identifier length
+    in bytes supported by the database to which the connection has been
+    established.  See `Database Object Naming Rules
+    <https://www.oracle.com/pls/topic/lookup?ctx=dblatest&
+    id=GUID-75337742-67FD-4EC0-985F-741C93D918DA>`__. The value may be
+    *undefined*, *30*, or *128*. The value *undefined* indicates the size
+    cannot be reliably determined by node-oracledb, which occurs when using
+    Oracle Client libraries 12.1 (or older) to connect to Oracle Database
+    12.2, or later.
+
 .. attribute:: connection.maxOpenCursors
 
     .. versionadded:: 6.3

doc/src/conf.py

@@ -35,7 +35,7 @@
 
 # General substitutions.
 project = 'node-oracledb'
-copyright = u'2015, 2024, Oracle and/or its affiliates'
+copyright = u'2015, 2025, Oracle and/or its affiliates'
 author = 'Oracle'
 
 # The default replacements for |version| and |release|, also used in various

doc/src/license.rst

@@ -10,7 +10,7 @@ License
 
 .. centered:: **LICENSE AGREEMENT FOR node-oracledb**
 
-Copyright |copy| 2015, 2024 Oracle and/or its affiliates.
+Copyright |copy| 2015, 2025 Oracle and/or its affiliates.
 
 This software is dual-licensed to you under the Universal Permissive License
 (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License

doc/src/release_notes.rst

@@ -19,6 +19,9 @@ Common Changes
 #)  Fixed :attr:`~dbObject.length` property for the database object
     collection types, which was broken from node-oracledb 6.0.
 
+#)  Added support for returning maximum identifier length allowed by the
+    database using the new property :attr:`connection.maxIdentifierLength`.
+
 Thin Mode Changes
 +++++++++++++++++
 

examples/connect.js

@@ -1,4 +1,4 @@
-/* Copyright (c) 2015, 2024, Oracle and/or its affiliates. */
+/* Copyright (c) 2015, 2025, Oracle and/or its affiliates. */
 
 /******************************************************************************
  *
@@ -70,9 +70,12 @@ async function run() {
   try {
     // Get a non-pooled connection
     connection = await oracledb.getConnection(dbConfig);
-
     console.log('Connection was successful!');
 
+    // Check some connection properties
+    console.log('Maximum Open Cursors:', connection.maxOpenCursors);
+    console.log('Maximum Identifier Length:', connection.maxIdentifierLength);
+
   } catch (err) {
     console.error(err);
   } finally {

lib/connection.js

@@ -1,4 +1,4 @@
-// Copyright (c) 2016, 2024, Oracle and/or its affiliates.
+// Copyright (c) 2016, 2025, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -1216,6 +1216,16 @@ class Connection extends EventEmitter {
       this._impl.isHealthy());
   }
 
+  //---------------------------------------------------------------------------
+  // maxIdentifierLength
+  //
+  // Returns the maximum length of identifiers supported by the database to
+  // which this connection has been established.
+  //---------------------------------------------------------------------------
+  get maxIdentifierLength() {
+    return this._impl && this._impl.getMaxIdentifierLength();
+  }
+
   //---------------------------------------------------------------------------
   // maxOpenCursors
   //

lib/impl/connection.js

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, 2023, Oracle and/or its affiliates.
+// Copyright (c) 2022, 2025, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -289,6 +289,16 @@ class ConnectionImpl {
     errors.throwNotImplemented("getting the internal name");
   }
 
+  //---------------------------------------------------------------------------
+  // getMaxIdentifierLength()
+  //
+  // Returns the maximum length of identifiers supported by the database to
+  // which this connection has been established.
+  //---------------------------------------------------------------------------
+  getMaxIdentifierLength() {
+    errors.throwNotImplemented("getting the maximum identifier length");
+  }
+
   //---------------------------------------------------------------------------
   // getMaxOpenCursors()
   //

lib/thin/connection.js

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, 2024, Oracle and/or its affiliates.
+// Copyright (c) 2022, 2025, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -1312,6 +1312,14 @@ class ThinConnectionImpl extends ConnectionImpl {
     return this.maxOpenCursors;
   }
 
+  //---------------------------------------------------------------------------
+  // Returns the maximum length of identifiers supported by the database to
+  // which this connection has been established.
+  //---------------------------------------------------------------------------
+  getMaxIdentifierLength() {
+    return this.maxIdentifierLength;
+  }
+
   //---------------------------------------------------------------------------
   // Returns the Oracle Database service name associated with the connection.
   //---------------------------------------------------------------------------

lib/thin/protocol/messages/auth.js

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, 2023, Oracle and/or its affiliates.
+// Copyright (c) 2022, 2025, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -342,6 +342,7 @@ class AuthMessage extends Message {
       this.conn.maxOpenCursors = Number(this.sessionData['AUTH_MAX_OPEN_CURSORS'] || 0);
       this.conn.serviceName = this.sessionData['AUTH_SC_SERVICE_NAME'];
       this.conn.instanceName = this.sessionData['AUTH_INSTANCENAME'];
+      this.conn.maxIdentifierLength = Number(this.sessionData['AUTH_MAX_IDEN_LENGTH'] || 30);
       const fullVersionNum = Number(this.sessionData['AUTH_VERSION_NO']);
       const versionNum = (fullVersionNum >> 24) & 0xFF;
       this.conn.warning = this.warning;

src/njsConnection.c

@@ -1,4 +1,4 @@
-// Copyright (c) 2015, 2024, Oracle and/or its affiliates.
+// Copyright (c) 2015, 2025, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -49,6 +49,7 @@ NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getExternalName);
 NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getInstanceName);
 NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getInternalName);
 NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getMaxOpenCursors);
+NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getMaxIdentifierLength);
 NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getOracleServerVersion);
 NJS_NAPI_METHOD_DECL_SYNC(njsConnection_getOracleServerVersionString);
 NJS_NAPI_METHOD_DECL_ASYNC(njsConnection_getQueue);
@@ -157,6 +158,8 @@ static const napi_property_descriptor njsClassProperties[] = {
             napi_default, NULL },
     { "getMaxOpenCursors", NULL, njsConnection_getMaxOpenCursors, NULL, NULL,
             NULL, napi_default, NULL },
+    { "getMaxIdentifierLength", NULL, njsConnection_getMaxIdentifierLength, NULL, NULL,
+            NULL, napi_default, NULL },
     { "getOracleServerVersion", NULL, njsConnection_getOracleServerVersion,
             NULL, NULL, NULL, napi_default, NULL },
     { "getOracleServerVersionString", NULL,
@@ -1236,6 +1239,29 @@ NJS_NAPI_METHOD_IMPL_SYNC(njsConnection_getMaxOpenCursors, 0, NULL)
     return true;
 }
 
+//-----------------------------------------------------------------------------
+// njsConnection_getMaxIdentifierLength()
+//   Get accessor of "maxIdentifierLength" property.
+//-----------------------------------------------------------------------------
+NJS_NAPI_METHOD_IMPL_SYNC(njsConnection_getMaxIdentifierLength, 0, NULL)
+{
+    njsConnection *conn = (njsConnection*) callingInstance;
+    dpiConnInfo connInfo;
+
+    if (conn->handle) {
+        if (dpiConn_getInfo(conn->handle, &connInfo) < 0)
+            return njsUtils_throwErrorDPI(env, globals);
+        // The check below is made, because Oracle Client does not return the
+        // max identifier length reliably when using Oracle Client
+        // 12.1 (or lower) to connect to Oracle Database 12.2 (or higher).
+        // See https://github.com/oracle/python-oracledb/issues/395
+        if (connInfo.maxIdentifierLength != 0)
+            NJS_CHECK_NAPI(env, napi_create_uint32(env, connInfo.maxIdentifierLength,
+                    returnValue))
+    }
+    return true;
+}
+
 
 //-----------------------------------------------------------------------------
 // njsConnection_getExecuteManyOutBinds()