RecordSet

RecordSet model concept is very similar to DataTable/DataRow from full .NET Framework: this is in-memory representation of data rows. This structure is very lightweight (in comparing to DataTable) and can be used with large results (many thousands of rows).

RecordSet can be populated from a select query:

DbDataAdapter dbAdapter; // lets assume that we have configured DbDataAdapter
var userRS = dbAdapter.Select( new Query("Users") ).ToRecordSet();
IDataReader rdr; // lets assume that we have a data reader
var someRS = new RecordSet(rdr);

When RecordSet is created in this way, schema is automatically inferred by data reader. Unlike DataTable, RecordSet doesn't bound to concrete table name, but it knows about rows columns and (optionally) about primary key:

foreach (var column in userRS.Columns) {
	Console.WriteLine($"Column: {column.Name} Type: {column.DataType}");
}

Empty RecordSet may be created programmatically:

var newRS = new RecordSet( new[] {
	new RecordSet.Column("id", typeof(int) ),
	new RecordSet.Column("name", typeof(string) )
} );
newRS.Columns["id"].AutoIncrement = true; // this metadata is needed to avoid inserting/updating autoincrement columns
newRS.SetPrimaryKey("id"); // composite primary keys are also supported

Like DataRow, RecordSet.Row has State property. It is used to determine what SQL command (insert, update or delete) should be used when RecordSet is committed to the database:

var newRow = newRS.Add();  // newRow.State is 'Added'
newRow["name"] = "Bart Simpson";
dbAdapter.Update("Users", newRS); // adapted inserts newRow and it becomes 'Unchanged'
newRow["name"] = "Gomer Simpson"; // 'Modified' flag is added to the newRow.State 
dbAdapter.Update("Users", newRS); // adapter updates newRow and it again becomes 'Unchanged'
newRow.Delete(); // newRow.State becomes 'Deleted'
dbAdapter.Update("Users", newRS); // adapter deletes newRow