The table below shows the ADO Data Type mapping between Access, SQL Server, and Oracle:

DataType EnumValueAccessSQLServerOracleadBigInt20 BigInt (SQL Server 2000 +) adBinary128 Binary
TimeStampRaw *adBoolean11YesNoBit adChar129 CharCharadCurrency6CurrencyMoney
SmallMoney adDate7DateDateTime adDBTimeStamp135DateTime (Access 97 (ODBC))DateTime
SmallDateTimeDateadDecimal14  Decimal *adDouble5DoubleFloatFloatadGUID72ReplicationID (Access 97 (OLEDB)), (Access 2000 (OLEDB))UniqueIdentifier (SQL Server 7.0 +) adIDispatch9   adInteger3AutoNumber
Integer
LongIdentity (SQL Server 6.5)
Int
 Int *adLongVarBinary205OLEObjectImageLong Raw *
Blob (Oracle 8.1.x)adLongVarChar201Memo (Access 97)
Hyperlink (Access 97)TextLong *
Clob (Oracle 8.1.x)adLongVarWChar203Memo (Access 2000 (OLEDB))
Hyperlink (Access 2000 (OLEDB))NText (SQL Server 7.0 +)NClob (Oracle 8.1.x)adNumeric131Decimal (Access 2000 (OLEDB))Decimal
NumericDecimal
Integer
Number
SmallIntadSingle4SingleReal adSmallInt2IntegerSmallInt adUnsignedTinyInt17ByteTinyInt adVarBinary204ReplicationID (Access 97)VarBinary adVarChar200Text (Access 97)VarCharVarCharadVariant12 Sql_Variant (SQL Server 2000 +)VarChar2adVarWChar202Text (Access 2000 (OLEDB))NVarChar (SQL Server 7.0 +)NVarChar2adWChar130 NChar (SQL Server 7.0 +) 

* In Oracle 8.0.x - decimal and int are equal to number and number(10).