using System.Data.SqlClient; // ... IDataParameter parameter = new SqlParameter("@Name", SqlDbType.NVarChar, 50); parameter.Value = "John Doe"; command.Parameters.Add(parameter);In this example, we use the SqlParameter class, which implements the IDataParameter interface, to create a parameter for a SQL command. The parameter has a name of "@Name", data type of NVarChar, and a length of 50. We then set the value of the parameter to "John Doe" and add it to the command's Parameters collection. Package Library: System.Data.Common (Assembly: System.Data.dll)