ADO数据类型转换

ADO DataType Enum	ADO DataType Enum Value	.NET Framework	SQL Server	Size	Access	Oracle	Visual Basic 6.0
adBigInt	20	Int64 SqlDbType.BigInt 10 OleDbType.BigInt 11	bigint 9	8			Variant
adBinary	128	Byte[] SqlDbType.VarBinary 10 OleDbType.Binary 11	binary timestamp	50 8		Raw 7	Variant
adBoolean	11	Boolean SqlDbType.Bit 10 OleDbType.Boolean 11	bit	1 2	YesNo		Boolean
adBSTR	8	String OleDbType.BSTR 11
adChapter	136	(DataReader)
adChar	129	String  SqlDbType.Char 10 OleDbType.Char 11	char	X		Char	String
adCurrency	6	Decimal SqlDbType.Money 10 OleDbType.Currency 11	money smallmoney	8 4 0	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.DateTime 10 OleDbType.DBTimeStamp 11	datetime  smalldatetime	8 4 0	DateTime 1	Date	Date
adDecimal	14	Decimal OleDbType.Decimal 11				Decimal 7	Variant 6
adDouble	5	Double SqlDbType.Float 10 OleDbType.Double 11	float	8 0	Double	Float	Double
adEmpty	0	Empty 11
adError	10	External-Exception OleDbType.Error 11
adFileTime	64	DateTime OleDbType.Filetime 11
adGUID	72	Guid  SqlDbType.UniqueIdentifier 10 OleDbType.Guid 11	uniqueidentifier5	16	ReplicationID2,3		Variant
adIDispatch	9	Object OleDbType.IDispatch 11
adInteger	3	Int32 SqlDbType.Int 10 OleDbType.Integer 11	identity 4 int	4 4	AutoNumber Long Integer	Int 7	Long
adIUnknown	13	Object OleDbType.IUnknown 11
adLongVarBinary	205	Byte[] SqlDbType.VarBinary 10 OleDbType.LongVarBinary 11	image	2147483647	OLEObject	Long Raw 7 Blob 8	Variant
adLongVarChar	201	String SqlDbType.VarChar 10 OleDbType.LongVarChar 11	text	2147483647	Memo 1, 2 Hyperlink 1, 2	Long 7 Clob 8	String
adLongVarWChar	203	String SqlDbType.NText 10 OleDbType.VarWChar 11	ntext 5	1073741823	Memo 3 Hyperlink 3	NClob 8	String
adNumeric	131	Decimal SqlDbType.Decimal 10 OleDbType.Decimal 11	decimal numeric	9	Decimal 3	Decimal Integer Number SmallInt	Variant 6
adPropVariant	138	Object OleDbType.PropVariant 11
adSingle	4	Single SqlDbType.Real 10 OleDbType.Single 11	real	4	Single		Single
adSmallInt	2	Int16, SqlDbType.SmallInt 10 OleDbType.SmallInt 11	smallInt	2	Integer		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.TinyInt 10 OleDbType.UnsignedTinyInt 11	tinyInt	1	Byte		Byte
adUserDefined	132
adVarBinary	204	Byte[]  SqlDbType.VarBinary 10 OleDbType.VarBinary 11	varbinary	50	ReplicationID 1		Variant
adVarChar	200	String SqlDbType.VarChar 10 OleDbType.VarChar 11	varchar	X	Text 1, 2	VarChar	String
adVariant	12	Object SqlDbType.Variant 10 OleDbType.Variant 11	sql_variant 9	8016		VarChar2	Variant
adVarNumeric	139	OleDbType.VarNumeric 11
adVarWChar	202	String SqlDbType.NVarChar 10 OleDbType.VarWChar 11	nvarchar 5	X	Text 3	NVarChar2	String
adWChar	130	String SqlDbType.NChar 10 OleDbType.WChar 11	nchar 5	X			String