DB2 to .NET type mapping

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

DB2 data types	SSDL1	CSDL1	.NET
SMALLINT	smallint	Int16	System.Int16
INTEGER	integer	Int32	System.Int32
BIGINT	bigint	Int64	System.Int64
REAL	real	Single	System.Single
DOUBLE, FLOAT	double, float	Double	System.Double
DECIMAL, NUMERIC, DECFLOAT	decimal, numeric, decfloat	Decimal	System.Decimal
DATE, TIMESTAMP	date, timestamp	DateTime	System.DateTime
TIME	time	Time	System.TimeSpan
CHAR, VARCHAR, LONG VARCHAR2, CLOB, GRAPHIC, VARGRAPHIC, LONG VARGRAPHIC2, DBCLOB, XML, DATALINK	char, varchar, long varchar, clob, graphic, vargraphic, long vargraphic, dbclob, xml, datalink	String	System.String
CHAR FOR BIT DATA, VARCHAR FOR BIT DATA, LONG VARCHAR FOR BIT DATA2, BLOB	char for bit data, varchar for bit data, long varchar for bit data, blob	Binary	System.Byte[]

The following mapping is optional. In Entity Developer you may tweak type mapping rules before creating the model, while for EDM Wizard/LightSwitch you need to modify XML mapping code manually after generating a model.

DB2 data types	SSDL1	CSDL1	.NET
CHAR(1)	yes no char as boolean	Boolean	System.Boolean
SMALLINT	boolean	Boolean	System.Boolean
SMALLINT	byte	Byte	System.Byte
SMALLINT	sbyte	SByte	System.SByte
CHAR(16) FOR BIT DATA	guid	Guid	System.Guid

.NET to DB2 default type mapping

.NET	CSDL1	SSDL1	DB2 data types
System.Boolean	Boolean	boolean	SMALLINT
System.Byte	Byte	byte	SMALLINT
System.Byte[]	Binary	char for bit data, varchar for bit data, blob3	CHAR FOR BIT DATA, VARCHAR FOR BIT DATA, BLOB3
System.DateTime	DateTime	timestamp	TIMESTAMP
System.DateTimeOffset	DateTimeOffset	not supported4	not supported4
System.Decimal	Decimal	decimal	DECIMAL
System.Double	Double	double	DOUBLE
System.Guid	Guid	guid	CHAR(16) FOR BIT DATA
System.Int16	Int16	smallint	SMALLINT
System.Int32	Int32	integer	INTEGER
System.Int64	Int64	bigint	BIGINT
System.SByte	SByte	sbyte	SMALLINT
System.Single	Single	real	REAL
System.String	String	char, varchar, clob, graphic, vargraphic, dbclob5	CHAR, VARCHAR, CLOB, GRAPHIC, VARGRAPHIC, DBCLOB5
System.TimeSpan	Time	time	TIME

¹ 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.

² IBM officially does not recommend to use LONG VARCHAR, LONG VARGRAPHIC and LONG VARCHAR FOR BIT DATA datatypes.

³ Mapping depends on MaxLength and FixedLength facets.

⁴ DB2 for LUW does not support a data type, which can store and process the System.DateTimeOffset type.

⁵ Mapping depends on MaxLength, FixedLength, and Unicode facets.

See Also

Entity Framework  | Using CHAR(1) mapped to System.Boolean in Entity Framework