我有两个返回结果集的 LinqToSql 查询:
var grResults = (from g in ctx.GeneralRequests
join rt in ctx.RequestTypes on g.RequestTypeId equals rt.RequestTypeId
join sub in ctx.Logins on g.SubmitterStaffId equals sub.LoginId
join onb in ctx.Logins on g.OnBehalfOfStaffId equals onb.LoginId
where sub.GadId == gadId
select new
{
Status = "Submitted",
RequestId = g.GeneralRequestId,
Submitter = sub.UserName,
OnBehalf = (onb == null ? string.Empty : onb.UserName),
RequestType = (rt == null ? string.Empty : rt.Description),
ProjectName = (g == null ? string.Empty : g.ProjectName) ,
Comments = (g == null ? string.Empty : g.Comments),
LastUpdate = g.LastUpdateDate
});
var grdResults = (from gd in ctx.GeneralRequestDrafts
join rt in ctx.RequestTypes on gd.RequestTypeId equals rt.RequestTypeId
into tempRequestTypes
from rt1 in tempRequestTypes.DefaultIfEmpty()
join onb in ctx.Logins on gd.OnBehalfOfStaffId equals onb.LoginId
into tempOnBehalf
from onb1 in tempOnBehalf.DefaultIfEmpty()
join sub in ctx.Logins on gd.SubmitterStaffId equals sub.LoginId
where sub.GadId == gadId
select new
{
Status = "Draft",
RequestId = gd.GeneralRequestDraftId,
Submitter = sub.UserName,
OnBehalf = (onb1 == null ? string.Empty : onb1.UserName),
RequestType = (rt1 == null ? string.Empty : rt1.Description),
ProjectName = (gd.ProjectName == null ? string.Empty : gd.ProjectName),
Comments = (gd.Comments == null ? string.Empty : gd.Comments),
LastUpdate = gd.LastUpdateDate
});
问题是当我尝试将它们联合起来时。
var results = grResults.Union(grdResults).OrderByDescending(r => r.LastUpdate);
即使两个单独的查询返回任何记录。
最佳答案
由于这两个查询似乎并不相互依赖,因此如果您只是想获取一个列表,只需执行两个查询并将每个查询的结果合并即可。
var results = grResults.ToList().Union(grdResults.ToList())
.OrderByDescending(r => r.LastUpdate);
关于c# - 联合两个 Linq 查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33811510/