private async Task CreateService(SqlConnection cn, SqlTransaction tx, string name, string queueName, string contractName)
{
var cmdtext = @"select name from sys.services where name=@name";
var existing = await _sqlCommandExecutor.ExecuteScalarAsync <string>(cn, tx, cmdtext, new SqlParameter("@name", name));
if (!string.IsNullOrEmpty(existing))
{
return;
}
await _sqlCommandExecutor.ExecuteCommandAsync(cn, tx, $"CREATE SERVICE [{name}] ON QUEUE [{queueName}]([{contractName}]);");
}
/// <inheritdoc />
/// <summary>
/// Get an id from the specified queue.
/// </summary>
/// <param name="queue"></param>
/// <param name="cancellationToken">cancellationToken</param>
/// <returns>Next id from queue, null if no message arrives in one second.</returns>
public async Task <string> DequeueWork(QueueType queue, CancellationToken cancellationToken)
{
SqlConnection cn = new SqlConnection(_connectionString);
try
{
await cn.OpenAsync(cancellationToken);
var par = _config.GetByQueue(queue);
var sql = _dequeueWorkCommand.Replace("{queueName}", par.QueueName);
var msg = await _sqlCommandExecutor.ExecuteScalarAsync <object>(cn, null, sql);
return(msg is DBNull ? null : (string)msg);
}
finally
{
cn.Close();
}
}