/// <summary>
/// Creates a listener on the specified channel. When using a listener,
/// it may be helpful to also turn on keepalive in the database connection
/// string.
/// </summary>
/// <param name="channel">The channel to listen on.</param>
/// <returns>An event listener for the specified channel.</returns>
public async Task <PostgresEventListener> CreateListenerAsync(string channel)
{
var connection = await CreateConnectionAsync() as NpgsqlConnection;
await connection.OpenAsync();
var listener = new PostgresEventListener(connection);
using (var command = new NpgsqlCommand($"LISTEN {Dialect.FormatIdentifier(channel)}", connection))
{
await command.ExecuteNonQueryAsync();
}
return(listener);
}
/// <summary>
/// Writes the specified <paramref name="identifier"/> to the output stream.
/// </summary>
/// <param name="identifier">
/// The <see cref="SqlIdentifier"/> to write to the output stream.
/// </param>
public void WriteIdentifier(SqlIdentifier identifier)
{
EnsureNotDisposed();
if (identifier == null)
{
throw new ArgumentNullException(nameof(identifier));
}
for (int index = 0; index < identifier.Segments.Length; index++)
{
var segment = identifier.Segments[index];
if (index > 0)
{
WriteRaw(".");
WriteRaw(Dialect.FormatIdentifier(segment));
}
else
{
Write(Dialect.FormatIdentifier(segment));
}
}
}
