Dvorkin's task

// [14:34:56] Pavel  Dvorkin:
public async Task<bool> AddClanMember(int id, int newMemberId, int clanId, ClanRole role)
  {
   using (var connection = await GetConnection())
   {
    await ExecuteNonQueryAsync(connection, "LOCK TABLES userclan WRITE, clans WRITE;");

    if (await IsPlayerInClan(connection, newMemberId) || !await CanMemberBeAddedToClan(connection, clanId) || !await CanPlayerAddMembersToClan(connection, id, clanId))
    {
     await ExecuteNonQueryAsync(connection, "UNLOCK TABLES;");
     return false;
    }

    var rowsAffected = await ExecuteNonQueryAsync(
     connection,
     "INSERT INTO userclan (fid_user, fid_clan, fclanrole) VALUES (@id, @fid_clan, @fclanrole);",
     Param("@id", id),
     Param("@fid_clan", clanId),
     Param("@fclanrole", (int)role)
     );

    await ExecuteNonQueryAsync(connection, "UNLOCK TABLES;");
    return rowsAffected > 0;
   }
  }