public override void AddUsersToRoles()

in MySql.Web/src/RoleProvider.cs [167:229]
58 lines of code
18 McCabe index (conditional complexity)

    public override void AddUsersToRoles(string[] usernames, string[] rolenames)
    {
      if (rolenames == null || rolenames.Length == 0) return;
      if (usernames == null || usernames.Length == 0) return;

      foreach (string rolename in rolenames)
      {
        if (String.IsNullOrEmpty(rolename))
          throw new ArgumentException(Properties.Resources.IllegalRoleName, "rolenames");
        if (!RoleExists(rolename))
          throw new ProviderException(Properties.Resources.RoleNameNotFound);
      }

      foreach (string username in usernames)
      {
        if (String.IsNullOrEmpty(username))
          throw new ArgumentException(Properties.Resources.IllegalUserName, "usernames");
        if (username.IndexOf(',') != -1)
          throw new ArgumentException(Properties.Resources.InvalidCharactersInUserName);

        foreach (string rolename in rolenames)
        {
          if (IsUserInRole(username, rolename))
            throw new ProviderException(Properties.Resources.UserIsAlreadyInRole);
        }
      }

      using (MySqlConnection connection = new MySqlConnection(connectionString))
      {
        MySqlTransaction txn = null;
        try
        {
          connection.Open();
          txn = connection.BeginTransaction();
          MySqlCommand cmd = new MySqlCommand(
              "INSERT INTO my_aspnet_usersinroles VALUES(@userId, @roleId)", connection);
          cmd.Parameters.Add("@userId", MySqlDbType.Int32);
          cmd.Parameters.Add("@roleId", MySqlDbType.Int32);
          foreach (string username in usernames)
          {
            // either create a new user or fetch the existing user id
            long userId = SchemaManager.CreateOrFetchUserId(connection,
                username, app.FetchId(connection), true);
            foreach (string rolename in rolenames)
            {
              int roleId = GetRoleId(connection, rolename);
              cmd.Parameters[0].Value = userId;
              cmd.Parameters[1].Value = roleId;
              cmd.ExecuteNonQuery();
            }
          }
          txn.Commit();
        }
        catch (Exception ex)
        {
          if (txn != null)
            txn.Rollback();
          if (WriteExceptionsToEventLog)
            WriteToEventLog(ex, "AddUsersToRoles");
          throw;
        }
      }
    }