select top 1关联查父级名称

SELECT users.UserID AS Id,
       users.UserName,
       users.TrueName,
       users.Phone,
       users.Email,
       STUFF(
       (
           SELECT ',' + roles.Description
           FROM Accounts_UserRoles userroles
               LEFT JOIN Accounts_Roles roles
                   ON roles.RoleID = userroles.RoleID
           WHERE userroles.UserID = users.UserID
           FOR XML PATH('')
       ),
       1,
       1,
       ''
            ) AS RoleNames,
       (
           SELECT TOP 1
                  UserName
           FROM Accounts_Users sup
           WHERE sup.UserID = users.SuperiorId
                 AND users.SuperiorId IS NOT NULL
       ) AS SuperiorName,
       users.Activity,
       users.IsSuperior,
       users.DataRange,
       dept.DeptName
FROM Accounts_Users users
    LEFT JOIN DeptInfo dept
        ON dept.DeptId = users.DeptID
           AND dept.DelFlag = 0
WHERE users.IsDelete = 0
      AND users.ClientCode IS NULL;