AddColumnsFromInterface Method

Overview

The AddColumnsFromInterface method adds columns to a data table by reflecting over a POCO interface type. It collects the specified interface and its entire inheritance chain, then adds a column for each public instance property.

For each interface property, the method determines:

• Column name - property name.
• Data type - converted from the property CLR type into a POCO DataSet data type name.
• Nullability - detected from the property type / nullability metadata.

Columns are added using DataTableExtensions.AddColumn, so existing rows in the table are extended with the new columns.

Declaration

/// <summary>
/// Adds columns from interface with inheritance chain
/// </summary>
/// <param name="dataTable">Data table</param>
/// <param name="interfaceType">Interface type</param>
/// <exception cref="ArgumentException">Exception is thrown if specified type is not an interface</exception>
public static void AddColumnsFromInterface(this IDataTable? dataTable, Type interfaceType)

Namespace and Assembly

Namespace: PocoDataSet.Extensions
Assembly: PocoDataSet.Extensions.dll

Behavior

• If dataTable is null, returns immediately.
• Validates that interfaceType.IsInterface is true. Otherwise throws ArgumentException.
• Collects interfaceType and all inherited interfaces recursively.
• Iterates over each collected interface and adds columns for its public instance properties.
• Avoids duplicate columns when multiple interfaces in the chain define a property with the same name (case-sensitive, ordinal comparison).
• Adds each property as a column by calling: dataTable.AddColumn(columnName, dataTypeName, isNullable). Primary-key and foreign-key conventions (if any) are applied by AddColumn.

Usage Example

Assume there is an interface that defines the schema of an EmploymentType entity:

/// <summary>
/// Defines employment type functionality
/// </summary>
internal interface IEmploymentType
{
  int Id { get; set; }
  string Code { get; set; }
  string? Description { get; set; }
}

You can create a table and add columns from the interface:

// 1. Create an empty data set
IDataSet dataSet = DataSetFactory.CreateDataSet();

// 2. Add an empty table
IDataTable employmentTypeDataTable = dataSet.AddNewTable("EmploymentType");

// 3. Add columns from the POCO interface
employmentTypeDataTable.AddColumnsFromInterface(typeof(IEmploymentType));

Notes

• The method uses reflection and will add columns for all public instance properties in the interface inheritance chain.
• Columns are added one-by-one using AddColumn. If the table already contains a column with the same name, AddColumn will throw a KeyDuplicationException.
• Because AddColumn extends existing rows, calling AddColumnsFromInterface on a table with many rows may have a performance impact.

 

Table of Content POCO DataSet DataTable Extensions Group DataTable Members

 

---

Business Process Programming in .Net
© 2004–2026 Laskarzhevsky Software Inc.
Unless otherwise noted, the content of this website is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
Code examples are provided under the MIT License.
You are free to share and adapt the material provided that appropriate credit is given and any modifications are clearly indicated.
The information provided on this website is for educational purposes only.
The author and publisher make no warranties regarding the completeness or suitability of the information and are not responsible for any damages resulting from its use.