Oracle Data Type Mappings

The following table lists Oracle data types and their mappings to the OracleDataReader.

Oracle data type .NET Framework data type returned by OracleDataReader.GetValue OracleClient data type returned by OracleDataReader.GetOracleValue Remarks
BFILE Byte[] OracleBFile
BLOB Byte[] OracleLob
CHAR String OracleString
CLOB String OracleLob
DATE DateTime OracleDateTime
FLOAT Decimal OracleNumber This data type is an alias for the NUMBER data type, and is designed so that the OracleDataReader returns a System.Decimal or OracleNumber instead of a floating-point value. Using the .NET Framework data type can cause an overflow.
INTEGER Decimal OracleNumber This data type is an alias for the NUMBER(38) data type, and is designed so that the OracleDataReader returns a System.Decimal or OracleNumber instead of an integer value. Using the .NET Framework data type can cause an overflow.
INTERVAL YEAR TO MONTH Int32 OracleMonthSpan
INTERVAL DAY TO SECOND TimeSpan OracleTimeSpan
LONG String OracleString
LONG RAW Byte[] OracleBinary
NCHAR String OracleString
NCLOB String OracleLob
NUMBER Decimal OracleNumber Using the .NET Framework data type can cause an overflow.
NVARCHAR2 String OracleString
RAW Byte[] OracleBinary
REF CURSOR The Oracle REF CURSOR data type is not supported by the OracleDataReader object.
ROWID String OracleString
TIMESTAMP DateTime OracleDateTime
TIMESTAMP WITH LOCAL TIME ZONE DateTime OracleDateTime
TIMESTAMP WITH TIME ZONE DateTime OracleDateTime
UNSIGNED INTEGER Number OracleNumber This data type is an alias for the NUMBER(38) data type, and is designed so that the OracleDataReader returns a System.Decimal or OracleNumber instead of an unsigned integer value. Using the .NET Framework data type can cause an overflow.
VARCHAR2 String OracleString

The following table lists Oracle data types and the .NET Framework data types (System.Data.DbType and OracleType) to use when binding them as parameters.

Oracle data type DbType enumeration to bind as a parameter OracleType enumeration to bind as a parameter Remarks
BFILE BFile Oracle only allows binding a BFILE as a BFILE parameter. The .NET Data Provider for Oracle does not automatically construct one for you if you attempt to bind a non-BFILE value, such as byte[] or OracleBinary.
BLOB Blob Oracle only allows binding a BLOB as a BLOB parameter. The .NET Data Provider for Oracle does not automatically construct one for you if you attempt to bind a non-BLOB value, such as byte[] or OracleBinary.
CHAR AnsiStringFixedLength Char
CLOB Clob Oracle only allows binding a CLOB as a CLOB parameter. The .NET Data Provider for Oracle does not automatically construct one for you if you attempt to bind a non-CLOB value, such as System.String or OracleString.
DATE DateTime DateTime
FLOAT Single, Double, Decimal Float, Double, Number Size determines the System.Data.DBType and OracleType.
INTEGER SByte, Int16, Int32, Int64, Decimal SByte, Int16, Int32, Number Size determines the System.Data.DBType and OracleType.
INTERVAL YEAR TO MONTH Int32 IntervalYearToMonth OracleType is only available when using both Oracle 9i client and server software.
INTERVAL DAY TO SECOND Object IntervalDayToSecond OracleType is only available when using both Oracle 9i client and server software.
LONG AnsiString LongVarChar
LONG RAW Binary LongRaw
NCHAR StringFixedLength NChar
NCLOB NClob Oracle only allows binding a NCLOB as a NCLOB parameter. The .NET Data Provider for Oracle does not automatically construct one for you if you attempt to bind a non-NCLOB value, such as System.String or OracleString.
NUMBER VarNumeric Number
NVARCHAR2 String NVarChar
RAW Binary Raw
REF CURSOR Cursor For more information, see Oracle REF CURSORs.
ROWID AnsiString Rowid
TIMESTAMP DateTime Timestamp OracleType is only available when using both Oracle 9i client and server software.
TIMESTAMP WITH LOCAL TIME ZONE DateTime TimestampLocal OracleType is only available when using both Oracle 9i client and server software.
TIMESTAMP WITH TIME ZONE DateTime TimestampWithTz OracleType is only available when using both Oracle 9i client and server software.
UNSIGNED INTEGER Byte, UInt16, UInt32, UInt64, Decimal Byte, UInt16, Uint32, Number Size determines the System.Data.DBType and OracleType.
VARCHAR2 AnsiString VarChar

The InputOutput, Output, and ReturnValue ParameterDirection values used by the Value property of the OracleParameter object are .NET Framework data types, unless the input value is an Oracle data type (for example, OracleNumber or OracleString). This does not apply to REF CURSOR, BFILE, or LOB data types.

See Also

Oracle and ADO.NET
ADO.NET Managed Providers and DataSet Developer Center