Question

我有一张包含TeamName和CurrentStatus字段的表格。我正在制作一个linq查询来获取每个团队以及每个状态记录的数量：

var teamStatusCounts = models.GroupBy(x => new { x.CurrentStatus, x.TeamName })
                             .Select(g => new { g.Key, Count = g.Count() });

此查询的结果返回除count为0之外的所有计数。我需要获取没有特定团队记录和特定状态（其中count = 0）的行。

Answer 1

您可以为您期望的团队名称和状态设置单独的集合，并将缺少的集合添加到结果集

//assuming allTeamNamesAndStatuses is a cross joing of all 'CurrentStatus' and 'TeamNames'
var teamStatusCounts = models.GroupBy(x => new { x.CurrentStatus, x.TeamName })
                             .Select(g => new { g.Key, Count = g.Count() })
                             .ToList();

var missingTeamsAndStatuses = allTeamNamesAndStatuses
                   .Where(a=>
                      !teamStatusCounts.Any(b=>
                          b.Key.CurrentStatus == a.CurrentStatus 
                          && b.Key.TeamName == a.TeamName))
                   .Select(a=>new { 
                        Key = new {  a.CurrentStatus, a.TeamName  }, 
                        Count = 0 
                   });

teamStatusCounts.AddRange(emptyGroups);

I've created a fiddle demonstrating the answer as well

Answer 2

我会首先选择球队名称和状态：

var teams = models.Select(x => x.TeamName).Distinct().ToList();
var status = models.Select(x => x.CurrentStatus).Distinct().ToList();

如果您已经知道列表条目，可以跳过此步骤。

然后，您可以为每个团队选择，每个州都可以选择模型数量：

var teamStatusCounts = teams.SelectMany(team => states.Select(state =>
    new
    {
        TeamName = team,
        CurrentStatus = state,
        Count = models.Count(model =>
                    model.TeamName == team && model.CurrentStatus == state)
    }));

在linq结果中包括count = 0

2 个答案: