我有以下linq查询insde我的asp.net mvc web应用程序,它主要构建我们的仪表板,通过显示许多实体的count(): -
public SystemInformation GetSystemInfo(int pagesize)
{
var d = DateTime.Today;
string[] notservers = new string[] { "vmware virtual platform", "storage device", "router", "switch", "firewall" };
string[] types = new String[] { "server", "workstation" };
var tmpCustomCount = tms.CustomAssets.Sum(a => (int?)a.Quantity);
SystemInformation s = new SystemInformation()
{
AssetCount = new AssetCount() {
CustomerCount = entities.AccountDefinitions.Count(),
RackCount = tms.TMSRacks.Count(),
ServerCount = tms.TMSServers.Count(),
VirtualMachineCount = tms.TMSVirtualMachines.Count(),
StorageDeviceCount = tms.TMSStorageDevices.Count(),
FirewallCount = tms.TMSFirewalls.Count(),
SwitchCount = tms.TMSSwitches.Count(),
RouterCount = tms.TMsRouters.Count(),
DataCenterCount = tms.DataCenters.Count(),
CustomCount = tmpCustomCount == null ? 0 : tmpCustomCount.Value
//tms.CustomAssets==null? 0 : tms.CustomAssets.Sum(a => a.Quantity)
},
AdminAudit = AllIncludingAdminAudit("", auditinfo => auditinfo.SecurityTaskType, auditinfo2 => auditinfo2.AuditAction).OrderByDescending(a => a.DateTimeStart)
.Take(pagesize).ToList(),
LatestTechnology = tms.Technologies.Where(a=> !a.IsDeleted && a.IsCompleted).OrderByDescending(a => a.TechnologyID).Take(pagesize).ToList(),
IT360ServerNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && (a.SystemInfo.ISSERVER == true ) && !(notservers.Contains(a.SystemInfo.MODEL.Trim().ToLower()))).Count(),
IT360VMNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && (a.SystemInfo.ISSERVER == true) && a.SystemInfo.MODEL.Trim().Equals("VMware Virtual Platform", StringComparison.OrdinalIgnoreCase)).Count(),
IT360SDNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && a.SystemInfo.MODEL.Trim().Equals("Storage Device", StringComparison.OrdinalIgnoreCase)).Count(),
IT360SwitchNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && a.SystemInfo.MODEL.Trim().Equals("Switch", StringComparison.OrdinalIgnoreCase)).Count(),
IT360FirewallNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && a.SystemInfo.MODEL.Trim().Equals("Firewall", StringComparison.OrdinalIgnoreCase)).Count(),
IT360RouterNo = entities.Resources
.Where(a => String.IsNullOrEmpty(a.ASSETTAG) && a.SystemInfo.MODEL.Trim().Equals("Router", StringComparison.OrdinalIgnoreCase)).Count(),
DeleteNo = tms.TechnologyAudits.Where(a => ( EntityFunctions.TruncateTime(a.DateTimeEnd) == d && a.AuditAction.Name.ToLower() == "delete" && a.TechnologyID != null)).Count(),//TechnologyId != null so that only assets that have tags will be included in the count
CreateNo = tms.TechnologyAudits.Where(a => (EntityFunctions.TruncateTime(a.DateTimeEnd) == d && a.AuditAction.Name.ToLower() == "add" && a.TechnologyID != null)).Count(),
EditNo = tms.TechnologyAudits.Where(a => (EntityFunctions.TruncateTime(a.DateTimeEnd) == d && a.AuditAction.Name.ToLower() == "Edit" && a.TechnologyID != null)).Count(),
OtherNo = tms.TechnologyAudits.Where(a => (EntityFunctions.TruncateTime(a.DateTimeEnd) == d
&&
!((a.AuditAction.Name.ToLower() == "delete" && a.TechnologyID != null)
|| (a.AuditAction.Name.ToLower() == "add" && a.TechnologyID != null)
|| (a.AuditAction.Name.ToLower() == "edit" && a.TechnologyID != null)))).Count(),
};
return s;
}
模型类是: -
public class SystemInformation
{
public AssetCount AssetCount { get; set; }
public IPagedList<TechnologyAudit> TechnologyAudit { get; set; }
public ICollection<AdminAudit> AdminAudit { get; set; }
public ICollection<Technology> LatestTechnology { get; set; }
[Display(Name = "Server/s")]
public int IT360ServerNo { get; set; }
[Display(Name = "VM/s")]
public int IT360VMNo { get; set; }
[Display(Name = "SD/s")]
public int IT360SDNo { get; set; }
[Display(Name = "Switch/s")]
public int IT360SwitchNo { get; set; }
[Display(Name = "Firewall/s")]
public int IT360FirewallNo { get; set; }
[Display(Name = "Router/s")]
public int IT360RouterNo { get; set; }
[Display(Name = "Delete Opeartion/s")]
public int DeleteNo { get; set; }
[Display(Name = "Create Opeartion/s")]
public int CreateNo { get; set; }
[Display(Name = "Edit Opeartion/s")]
public int EditNo { get; set; }
[Display(Name = "Other Opeartion/s")]
public int OtherNo { get; set; }
public Double HourSpan { get; set; }
public int RefreshInSeconds { get; set; }
}
以上运行良好,但问题是我向DB发送单独的查询以填充每个变量,例如customercount,RackCount,ServerCount等... 我知道有单一查询来构建上面的内容可能是不可能的,因为我从单独的表中检索count()。但是有没有办法将同一个表上的Count()连接到单个查询,我的意思是使用诸如GroupBy之类的东西并根据where critical返回计数?
答案 0 :(得分:1)
GroupBy可用于计算与指定密钥有关的组计数。在您的示例中,在等于字符串键之后或之前使用了大量额外的过滤。您可以尝试以下情况,但在其他情况下,很难有效地应用GroupBy:
var ActionCounts = tms.TechnologyAudits.Where(a =>
(EntityFunctions.TruncateTime(a.DateTimeEnd) == d && a.TechnologyID != null))
.GroupBy(a => a.AuditAction.Name.ToLower())
.Select(g => new {
Action = g.Key
ItemCount = g.Count();
}).ToLookup(a => a.Action);
如何与您的代码集成:
var tmpCustomCount = tms.CustomAssets.Sum(a => (int?)a.Quantity);
[Insert here:]
SystemInformation s = new SystemInformation()
...
DeleteNo = ActionCounts["delete"] == null ? 0 : ActionCounts["delete"].Single().ItemCount;
CreateNo = ActionCounts["add"] == null ? 0 : ActionsCount["add"].Single().ItemCount;
EditNo = ActionCounts["edit"] == null ? 0 : ActionsCount["edit"].Single().ItemCount;