Data Type Mapping

The following table shows the ADO Data Type mapping between Visual Basic, Access, SQL Server, Oracle, and the .NET Framework.

ADO DataType Enum	ADO DataType Enum Value	Mapped Data Type	SQL Server	Size	Access	Oracle	Visual Basic 6.0
adBigInt	20	Int64 SqlDbType.BigInt¹⁰OleDbType.BigInt ¹¹ DBTYPE_I8 ⁹	bigint ⁹	8			Variant
adBinary	128	Byte[] SqlDbType.VarBinary¹⁰OleDbType.Binary ¹¹ DBTYPE_BYTES ⁹	binary timestamp	50 8	Binary LongBinary	Raw ⁷	Variant
adBoolean	11	Boolean SqlDbType.Bit¹⁰ OleDbType.Boolean ¹¹ DBTYPE_BOOL ⁹	bit	1 2	Bit YesNo		Boolean
adBSTR	8	String OleDbType.BSTR ¹¹
adChapter	136	(DataReader)
adChar	129	String SqlDbType.Char¹⁰OleDbType.Char ¹¹ DBTYPE_STR ⁹	char	x		Char	String
adCurrency	6	Decimal SqlDbType.Money ¹⁰OleDbType.Currency ¹¹ DBTYPE_CY ⁹	money smallmoney	8 4	Currency		Currency
adDate	7	DateTime OleDbType.DBDate ¹¹		0	DateTime ²		Date
adDBDate	133	DateTime OleDbType.DBDate ¹¹
adDBFileTime	137	DBFileTime ¹¹
adDBTime	134	DateTime OleDbType.DBTime ¹¹
adDBTimeStamp	135	DateTime SqlDbType.DateTime¹⁰OleDbType.DBTimeStamp ¹¹ DBTYPE_DBTIMESTAMP ⁹	datetime smalldatetime	8 4	DateTime ¹	Date	Date
adDecimal	14	Decimal OleDbType.Decimal ¹¹				Decimal ⁷	Variant ⁶
adDouble	5	Double SqlDbType.Float¹⁰OleDbType.Double ¹¹ DBTYPE_R8 ⁹	float	8	Double	Float	Double
adEmpty	0	Empty ¹¹
adError	10	External-Exception OleDbType.Error ¹¹
adFileTime	64	DateTime OleDbType.Filetime ¹¹
adGUID	72	Guid SqlDbType.UniqueIdentifier¹⁰OleDbType.Guid ¹¹ DBTYPE_R8 ⁹	uniqueidentifier ⁵	16	Guid ReplicationID ^2,3		Variant
adIDispatch	9	Object OleDbType.IDispatch ¹¹
adInteger	3	Int32 SqlDbType.Int¹⁰OleDbType.Integer ¹¹ DBTYPE_I4 ⁹	identity ⁴ int	4 4	Counter AutoNumber LongInteger	Int ⁷	Long
adIUnknown	13	Object OleDbType.IUnknown ¹¹
adLongVarBinary	205	Byte[] SqlDbType.VarBinary¹⁰OleDbType.LongVarBinary ¹¹ DBTYPE_BYTES ⁹	image	2147483647	OLEObject	Long Raw ⁷Blob ⁸	Variant
adLongVarChar	201	String SqlDbType.VarChar¹⁰OleDbType.LongVarChar ¹¹ DBTYPE_STR ⁹	text	2147483647	Memo ^{1, 2} Hyperlink ^{1, 2}	Long ⁷Clob ⁸	String
adLongVarWChar	203	String SqlDbType.NText¹⁰OleDbType.VarWChar ¹¹ DBTYPE_WSTR ⁹	ntext ⁵	1073741823	Memo ³ Hyperlink ³	NClob ⁸	String
adNumeric	131	Decimal SqlDbType.Decimal¹⁰OleDbType.Decimal ¹¹ DBTYPE_NUMERIC ⁹	decimal numeric	9	Decimal ³	Decimal Integer Number SmallInt	Variant ⁶
adPropVariant	138	Object OleDbType.PropVariant ¹¹
adSingle	4	Single SqlDbType.Real¹⁰OleDbType.Single ¹¹ DBTYPE_R4 ⁹	real	4	Single		Single
adSmallInt	2	Int16, SqlDbType.SmallInt¹⁰OleDbType.SmallInt ¹¹ DBTYPE_I2 ⁹	smallInt	2	Integer Short		Integer
adTinyInt	16	Byte OleDbType.TinyInt ¹¹
adUnsignedBigInt	21	UInt64 OleDbType.UnsignedBigInt ¹¹
adUnsignedInt	19	UInt32 OleDbType.UnsignedInt ¹¹
adUnsignedSmallInt	18	UInt16 OleDbType.UnsignedSmallInt ¹¹
adUnsignedTinyInt	17	Byte SqlDbType.TinyInt¹⁰OleDbType.UnsignedTinyInt ¹¹ DBTYPE_UI1 ⁹	tinyInt	1	Byte		Byte
adUserDefined	132
adVarBinary	204	Byte[] SqlDbType.VarBinary¹⁰OleDbType.VarBinary ¹¹ DBTYPE_BYTES ⁹	varbinary	50	ReplicationID ¹		Variant
adVarChar	200	String SqlDbType.VarChar¹⁰OleDbType.VarChar ¹¹ DBTYPE_STR ⁹	varchar	x	Text ^{1, 2} LongText	VarChar	String
adVariant	12	Object SqlDbType.Variant¹⁰ OleDbType.Variant ¹¹ DBTYPE_VARIANT ⁹ DBTYPE_SQLVARIANT ⁹	sql_variant ⁹	8016		VarChar2	Variant
adVarNumeric	139	OleDbType.VarNumeric ¹¹
adVarWChar	202	String SqlDbType.NVarChar¹⁰OleDbType.VarWChar ¹¹ DBTYPE_WSTR ⁹	nvarchar ⁵	x	Text ³	NVarChar2	String
adWChar	130	String SqlDbType.NChar¹⁰OleDbType.WChar ¹¹ DBTYPE_WSTR ⁹	nchar ⁵	x			String

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1 - ODBC Driver (3.51.171300): Microsoft Access Driver (*.mdb), Access 97 (3.5 format)
2 - OLE DB Provider: Microsoft.Jet.OLEDB.3.51, Access 97 (3.5 format)
3 - OLE DB Provider: Microsoft.Jet.OLEDB.4.0 , Access 2000 (4.0 format)
4 - OLE DB Provider: SQLOLEDB, SQL Server 6.5
5 - OLE DB Provider: SQLOLEDB, SQL Server 7.0 +
6 - The VB Decimal data type can only be used within a Variant, that is, you cannot declare
a VB variable to be of type Decimal.
7 - Oracle 8.0.x Note: DECIMAL and INT are synonyms for NUMBER and NUMBER(10) respectively.
8 - Oracle 8.1.x
9 - OLE DB Provider: SQLOLEDB, SQL Server 2000 +
10 - SQL Server .NET Data Provider (via System.Data.SqlTypes)
11 - OLE DB .NET Data Provider (via System.Data.OleDb)

Note: "User Defined" data types (e.g. ID, TID, EmpID, SysName) are not shown on this diagram.