.NET data types are defined as part of the common type system within .NET. The common type system supports two general categories of types, value types and reference types. Many ABL data types are mapped to built-in value types provided by .NET. Reference types are classes, either those provided by .NET or user-defined classes. Some ABL data types are mapped to .NET-provided classes, and a few are mapped to ABL-provided classes.

An ABL parameter is mapped directly to its corresponding .NET data type or OpenEdge-provided class, as shown in the following table. These mappings also apply to user-defined function return types, although LONGCHAR and MEMPTR types cannot be returned across the Open Client interface.

CHARACTER

System.String

COM-HANDLE

Progress.Open4GL.COMHandle

DATASET

DATASET-HANDLE

System.Data.DataSet

DATE
DATETIME
DATETIME-TZ

System.DateTime

DECIMAL

System.Decimal

HANDLE

Progress.Open4GL.Handle

INT64

System.Int64

INTEGER

System.Int32

LOGICAL

System.Boolean

LONGCHAR

System.String

MEMPTR

Progress.Open4GL.Memptr

RAW

System.Byte[ ]

RECID

System.Int64

ROWID

Progress.Open4GL.Rowid

TABLE

TABLE-HANDLE

System.Data.DataTable

WIDGET-HANDLE

Progress.Open4GL.Handle

The COM-HANDLE, HANDLE, RECID, ROWID, and WIDGET-HANDLE data types are not meaningful outside the ABL environment. Their use is restricted to obtaining the value from an ABL procedure and passing it back to another ABL procedure.

The mapping for the individual fields of a temp-table or temp-tables within a ProDataSet differs from that of other parameters. For information on data type mapping for fields within these parameters, see Data type mapping for temp-table fields.

.NET Open Clients do not support the ABL BUFFER parameter.