public static async Task <Taxon[]> GetSubtaxaAsync(Taxon taxon)
{
List <Taxon> result = new List <Taxon>();
string table_name = Taxon.TypeToDatabaseTableName(taxon.GetChildRank());
string parent_column_name = Taxon.TypeToDatabaseColumnName(taxon.type);
if (string.IsNullOrEmpty(table_name))
{
return(result.ToArray());
}
string query = "SELECT * FROM {0} WHERE {1} = $parent_id";
using (SQLiteCommand cmd = new SQLiteCommand(string.Format(query, table_name, parent_column_name))) {
cmd.Parameters.AddWithValue("$parent_id", taxon.id);
using (DataTable rows = await Database.GetRowsAsync(cmd))
foreach (DataRow row in rows.Rows)
{
result.Add(Taxon.FromDataRow(row, taxon.GetChildRank()));
}
}
// Sort taxa alphabetically by name.
result.Sort((lhs, rhs) => lhs.name.CompareTo(rhs.name));
return(result.ToArray());
}
public static async Task DeleteTaxonAsync(Taxon taxon)
{
string table_name = _getRankTableName(taxon.type);
string subtaxa_table_name = _getRankTableName(taxon.GetChildRank());
string subtaxa_column_name = _getRankColumnName(taxon.type);
// Set to NULL any references subtaxa have to this taxon.
// Note that this can also happen automatically if the foreign key is set up correctly when creating the database.
if (!string.IsNullOrEmpty(table_name) && !string.IsNullOrEmpty(subtaxa_column_name))
{
using (SQLiteCommand cmd = new SQLiteCommand(string.Format("UPDATE {0} SET {1} = NULL WHERE {1} = $id", subtaxa_table_name, subtaxa_column_name))) {
cmd.Parameters.AddWithValue("$id", taxon.id);
await Database.ExecuteNonQuery(cmd);
}
}
// Delete the taxon.
if (!string.IsNullOrEmpty(table_name))
{
using (SQLiteCommand cmd = new SQLiteCommand(string.Format("DELETE FROM {0} WHERE id = $id", table_name))) {
cmd.Parameters.AddWithValue("$id", taxon.id);
await Database.ExecuteNonQuery(cmd);
}
}
}
