Oracle to .NET type mapping

Type mapping rules from this table are used by default when generating a model from a database with Entity Data Model Wizard in Visual Studio 2008 - 2022 and Create Model Wizard in Entity Developer.

You may override the default mapping for numeric types in Entity Data Model Wizard using the OracleConnection.NumberMappings property.

Oracle data types	SSDL1	CSDL1	.NET
NUMBER(1)	bool	Boolean	System.Boolean
NUMBER(2)..NUMBER(9)2	int	Int32	System.Int32
NUMBER(10)..NUMBER(18)2	int64	Int64	System.Int64
NUMBER (p, s), where 0 < s < p < 162	double	Double	System.Double
other NUMBERs	decimal	Decimal	System.Decimal
FLOAT, REAL, BINARY_FLOAT3, BINARY_DOUBLE3	the same3	Decimal	System.Decimal
DATE, TIMESTAMP, TIMESTAMP WITH TIME ZONE, TIMESTAMP WITH LOCAL TIME ZONE	the same4	DateTime	System.DateTime
INTERVAL DAY TO SECOND	the same4	Time	System.TimeSpan
CHAR, NCHAR, VARCHAR2, NVARCHAR2, CLOB, NCLOB, ROWID, UROWID, XMLTYPE, INTERVAL YEAR TO MONTH, LONG5	the same4	String	System.String
BLOB, RAW6, LONG RAW5	the same4	Binary	System.Byte[]
PL/SQL BOOLEAN	the same4	Boolean	System.Boolean
RAW(16)	guid	Guid	System.Guid
PL/SQL BOOLEAN	the same4	Boolean	System.Boolean
SDO_GEOMETRY7	sdo_geometry4	Geometry, GeometryCollection, GeometryLineString, GeometryMultiLineString, GeometryMultiPoint, GeometryMultiPolygon, GeometryPoint, GeometryPolygon	DbGeometry
SDO_GEOMETRY7	sdo_geography4	Geography, GeographyCollection, GeographyLineString, GeographyMultiLineString, GeographyMultiPoint, GeographyMultiPolygon, GeographyPoint, GeographyPolygon	DbGeography

¹ Applicable only to Entity Framework v1 - v6. Not applicable to Entity Framework Core, because Entity Framework Core does not support XML mapping.

² The negative scale cases are taken into account.

³ BINARY_DOUBLE and BINARY_FLOAT data types appeared in Oracle 10g.

⁴ These SSDL types completely identical to the corresponding Oracle data types.

⁵ According to official Oracle recomendations, using of LONG and LONG RAW data types is not recommended.

⁶ All RAW types, except RAW(16).

⁷ Supported in Entity Framework v5 and v6.

.NET to Oracle default type mapping

.NET	CSDL1	SSDL1	Oracle data types
System.Boolean	Boolean	bool	NUMBER(1)
System.Byte	Byte	byte	NUMBER(3)2
System.Byte[]	Binary	BLOB	BLOB
DbGeometry3	Geometry	sdo_geometry	SDO_GEOMETRY
DbGeography3	Geography	sdo_geography	SDO_GEOMETRY
System.DateTime	DateTime	TIMESTAMP	TIMESTAMP
System.DateTimeOffset	DateTimeOffset	datetimeoffset	TIMESTAMP WITH TIME ZONE
System.Decimal	Decimal	decimal	NUMBER4
System.Double	Double	double	NUMBER
System.Guid	Guid	guid	RAW(16)
System.Int16	Int16	int16	NUMBER(5)2
System.Int32	Int32	int	NUMBER(10)2
System.Int64	Int64	int64	NUMBER(19)2
System.SByte	SByte	sbyte	NUMBER(3)2
System.Single	Single	single	NUMBER(15,5)2
System.String	String	VARCHAR2	VARCHAR2
System.TimeSpan	Time	INTERVAL DAY TO SECOND	INTERVAL DAY TO SECOND

¹ Applicable only to Entity Framework v1 - v6. Not applicable to Entity Framework Core, because Entity Framework Core does not support XML mapping.

² Note that when mapping corresponding database data type, you will need the .NET type with larger precision. That is because, for example, any Int32 value can be stored in the NUMBER(10) column, but largest NUMBER(10) column value cannot be stored in the Int32 field, it requires Int64 field.

³ Supported in Entity Framework v5 and v6.

⁴ Mapping of this type depends on the DecimalPropertyConvention. If this convention is enabled (it is enabled by default), System.Decimal is mapped to NUMBER(18,2). Otherwise, it is mapped to NUMBER.