Question

我有一个包含大约100列和30000行的表。看起来像这样：

site_id   cell_id   sector_id    value1     value2
  1          1           1          70        23
  1          2           1          40        20
  1          3           1          67        35
  1          5           2          42        60
  1          6           2          65        30
  1          7           2          62        62
  2          11          1          67        11
  2          12          1          45        22
  2          13          1          65        15

对于一个site_id的相同sector_id，如果value1＆gt; = 65，那么value2 <25的相同扇区中的任何cell_id将被归类为“LOW_LOAD_CELL”。期望的输出将是：

site_id   cell_id   sector_id    value1     value2   cell_status
  1          1           1          70        23     LOW_LOAD_CELL
  1          2           1          40        20     LOW_LOAD_CELL
  1          3           1          67        35
  1          5           2          42        60
  1          6           2          65        30
  1          7           2          62        62
  2          11          1          67        11     LOW_LOAD_CELL
  2          12          1          45        22     LOW_LOAD_CELL
  2          13          1          65        15     LOW_LOAD_CELL
 ...

老实说，我不知道如何在SQL中使用。我已经尝试过WHEN CASE，但是当我需要为value2写条件时，我就堆积了。

Answer 1

尝试：

    [AttributeUsage(AttributeTargets.Class)]
    public class UserMigrationAttribute : ActionFilterAttribute
    {
        public ApplicationSignInManager SignInManager(ActionExecutingContext filterContext)
        {
            return filterContext.HttpContext.GetOwinContext().Get<ApplicationSignInManager>();
        }

        public UserManager UserManager(ActionExecutingContext filterContext)
        {
            return filterContext.HttpContext.GetOwinContext().GetUserManager<UserManager>();
        }

        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            CreateMigrateCurrentUser(filterContext);
            base.OnActionExecuting(filterContext);
        }

        private static readonly object LockThis = new object();

        private void CreateMigrateCurrentUser(ActionExecutingContext filterContext)
        {
            lock (LockThis)
            {
                var signInManager = SignInManager(filterContext);
                var userManager = UserManager(filterContext);

                var sessionTrackId = GetSessionTrackId(filterContext);

                if (!filterContext.HttpContext.Request.IsAuthenticated)
                {
                    if (!string.IsNullOrEmpty(sessionTrackId))
                    {
                        var username = string.Format("{0}@mydomain.com", sessionTrackId);
                        var user = userManager.FindByName(username);

                        if (user == null)
                        {
                            user = new User() {UserName = username, Email = username};
                            var result = userManager.Create(user);
                            userManager.AddToRole(user.Id, StringResources.AnonymousVisitorsGroup);
                        }

                        signInManager.SignIn(user, true, true);
                    }
                }
                else
                {
                    if (!string.IsNullOrEmpty(sessionTrackId))
                    {
                        var username = string.Format("{0}@mydomain.com", sessionTrackId);
                        var user = userManager.FindByName(username);

                        if (user != null)
                        {
                            if (!HttpContext.Current.User.IsInRole(StringResources.AnonymousVisitorsGroup))
                            {
                                var targetUserId = HttpContext.Current.User.Identity.GetUserId<int>();

                                var service = new Service();
                                service.Users.MigrateUser(user.Id, targetUserId);
                            }
                        }
                    }
                }

            }

        }

        private string GetSessionTrackId(ActionExecutingContext filterContext)
        {
            var retVal = string.Empty;
            if (filterContext.HttpContext.Request.Cookies["stid"] != null)
            {
                retVal = filterContext.HttpContext.Request.Cookies["stid"].Value;
            }

            return retVal;

        }

    }

Answer 2

我认为你真正想要的逻辑是：

select t.*,
       (case when max(value1) over (partition by site_it, sector_id) >= 65 and
                  value2 < 25
             then 'LOW_LOAD_CELL'
        end) as cell_status 
from t ;

这符合您的数据 - 如果扇区/站点组合的任何行的value1为65或更高，则当该value2小于25时，该单元格是低负载单元格。

Answer 3

你可以试试这个：

select t.*, case when t2.cnt > 0 and value2 < 25 then 'LOW_LOAD_CELL' end cell_status
from mytable as t left join
( select site_id, sector_id, count(*) cnt from mytable where 
  value1 >= 65 group by site_id, sector_id ) as  t2
on t.site_id = t2.site_id and t.sector_id = t2.sector_id

PostgreSQL中的不同行中有两列条件

3 个答案: