private async Task <IFetchedMessage> FetchNextMessageCoreAsync(string sql, object args = null)
{
//here don't use `using` to dispose
var connection = new MySqlConnection(_options.ConnectionString);
await connection.OpenAsync();
var transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted);
FetchedMessage fetchedMessage = null;
try
{
fetchedMessage = await connection.QueryFirstOrDefaultAsync <FetchedMessage>(sql, args, transaction);
}
catch (MySqlException)
{
transaction.Dispose();
throw;
}
if (fetchedMessage == null)
{
transaction.Rollback();
transaction.Dispose();
connection.Dispose();
return(null);
}
return(new MySqlFetchedMessage(fetchedMessage.MessageId, fetchedMessage.MessageType, connection, transaction));
}
private async Task <IFetchedMessage> FetchNextMessageCoreAsync(string sql, object args = null)
{
//here don't use `using` to dispose
var connection = new MySqlConnection(Options.ConnectionString);
await connection.OpenAsync();
var transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted);
FetchedMessage fetchedMessage = null;
try
{
//fetchedMessage = await connection.QuerySingleOrDefaultAsync<FetchedMessage>(sql, args, transaction);
// An anomaly with unknown causes, sometimes QuerySingleOrDefaultAsync can't return expected result.
using (var reader = connection.ExecuteReader(sql, args, transaction))
{
while (reader.Read())
{
fetchedMessage = new FetchedMessage
{
MessageId = (int)reader.GetInt64(0),
MessageType = (MessageType)reader.GetInt64(1)
};
}
}
}
catch (MySqlException)
{
transaction.Dispose();
throw;
}
if (fetchedMessage == null)
{
transaction.Rollback();
transaction.Dispose();
connection.Dispose();
return(null);
}
return(new MySqlFetchedMessage(fetchedMessage.MessageId, fetchedMessage.MessageType, connection,
transaction));
}