Essential ADO.NET

A.5. Parameter.DbType

The .NET data provider type of a Parameter object is inferred from the .NET framework type of the Value of the Parameter object or from the DbType of the Parameter object, as shown in Table A-5.

Table A-5. Mapping Parameter.DbType to parameter values in .NET

.NET Framework Type	System.Data. DbType	SqlDbType	OleDbType
bool	Boolean	Bit	Boolean
byte	Byte	TinyInt	Unsigned-TinyInt
byte[]	Binary	VarBinary. This implicit conversion will fail if the byte array is greater than the maximum size of a VarBinary, which is 8,000 bytes. For byte arrays larger than 8,000 bytes, explicitly set the SqlDbType.	VarBinary
char		Inferring a SqlDbType from char is not supported.	Char
DateTime	DateTime	DateTime	DBTimeStamp
Decimal	Decimal	Decimal ...