allownullsenum.md

title	AllowNullsEnum | Microsoft Docs
ms.prod	sql
ms.prod_service	connectivity
ms.technology	connectivity
ms.custom
ms.date	01/19/2017
ms.reviewer
ms.topic	conceptual
apitype	COM
f1_keywords	AllowNullsEnum
helpviewer_keywords	AllowNullsEnum enumeration [ADOX]
ms.assetid	6acf3689-1a7f-4379-9d7f-df452ccbac27
author	MightyPen
ms.author	genemi

AllowNullsEnum

Specifies whether records with null values are indexed.

Constant	Value	Description
adIndexNullsAllow	0	The index does allow entries in which the key columns are null. If a null value is entered in a key column, the entry is inserted into the index.
adIndexNullsDisallow	1	Default. The index does not allow entries in which the key columns are null. If a null value is entered in a key column, an error will occur.
adIndexNullsIgnore	2	The index does not insert entries containing null keys. If a null value is entered in a key column, the entry is ignored and no error occurs.
adIndexNullsIgnoreAny	4	The index does not insert entries where some key column has a null value. For an index having a multi-column key, if a null value is entered in some column, the entry is ignored and no error occurs.

Applies To

IndexNulls Property (ADOX)