根据entityframework.codeplex.com的建议，我使用标记entity-framework发布此问题。
数据库：PostgreSQL 9.1 驱动程序：Npgsql 2.0.12
LINQ查询：
var q1 = customerComplaints
.Where(x => x.ParentId == null)
.Except(customerComplaints
.Where(x => customerComplaints
.Any(c => (c.ParentId == x.Id))));
var q2 =
(from a in customerComplaints
join b in
(customerComplaints.Where(a => a.ParentId != null)
.GroupBy(a => a.ParentId)
.Select(b => new { ParentId = b.Key, CreatedDate = b.Max(t => t.CreatedDate) }))
on a.ParentId equals b.ParentId
where a.CreatedDate == b.CreatedDate
select a);
q1 = q1.Union(q2);
// Apply Sorting
if (string.IsNullOrEmpty(sorting) || sorting.Equals("CustomerName ASC")) {
q1 = q1.OrderBy(p => p.Customer.Name);
} else if (sorting.Equals("CustomerName DESC")) {
q1 = q1.OrderByDescending(p => p.Customer.Name);
} else if (sorting.Equals("ManagerName ASC")) {
q1 = q1.OrderBy(p => p.Manager.LastName);
} else if (sorting.Equals("ManagerName DESC")) {
q1 = q1.OrderByDescending(p => p.Manager.LastName);
} else if (sorting.Equals("AssignedName ASC")) {
q1 = q1.OrderBy(p => p.Assigned.LastName);
} else if (sorting.Equals("AssignedName DESC")) {
q1 = q1.OrderByDescending(p => p.Assigned.LastName);
} else if (sorting.Equals("StatusName ASC")) {
q1 = q1.OrderBy(p => p.StatusId);
} else if (sorting.Equals("StatusName DESC")) {
q1 = q1.OrderByDescending(p => p.StatusId);
} else if (sorting.Equals("ComplaintType ASC")) {
q1 = q1.OrderBy(p => p.ComplaintTypeId);
} else if (sorting.Equals("ComplaintType DESC")) {
q1 = q1.OrderByDescending(p => p.ComplaintTypeId);
} else if (sorting.Equals("CreatedDate ASC")) {
q1 = q1.OrderBy(p => p.CreatedDate);
} else if (sorting.Equals("CreatedDate DESC")) {
q1 = q1.OrderByDescending(p => p.CreatedDate);
}
// Perform paging and execute query
var result = q1.Skip(startIndex).Take(pageSize).ToList();
结果SQL
SELECT
"Limit1"."C1" AS "C1"
"Limit1"."C2" AS "C2"
"Limit1"."C3" AS "C3"
"Limit1"."C4" AS "C4"
"Limit1"."C5" AS "C5"
"Limit1"."C6" AS "C6"
"Limit1"."C7" AS "C7"
"Limit1"."C8" AS "C8"
"Limit1"."C9" AS "C9"
"Limit1"."C10" AS "C10"
"Limit1"."C11" AS "C11"
"Limit1"."C12" AS "C12"
"Limit1"."C13" AS "C13"
"Limit1"."C14" AS "C14"
"Limit1"."C15" AS "C15"
"Limit1"."C16" AS "C16"
"Limit1"."C17" AS "C17"
"Limit1"."C18" AS "C18"
"Limit1"."C19" AS "C19"
"Limit1"."C20" AS "C20"
"Limit1"."C21" AS "C21"
"Limit1"."C22" AS "C22"
FROM
(SELECT DISTINCT
"UnionAll1"."C1" AS "C1"
"UnionAll1"."C2" AS "C2"
"UnionAll1"."C3" AS "C3"
"UnionAll1"."C4" AS "C4"
"UnionAll1"."C5" AS "C5"
"UnionAll1"."C6" AS "C6"
"UnionAll1"."C7" AS "C7"
"UnionAll1"."C8" AS "C8"
"UnionAll1"."C9" AS "C9"
"UnionAll1"."C10" AS "C10"
"UnionAll1"."C11" AS "C11"
"UnionAll1"."C12" AS "C12"
"UnionAll1"."C13" AS "C13"
"UnionAll1"."C14" AS "C14"
"UnionAll1"."C15" AS "C15"
"UnionAll1"."C16" AS "C16"
"UnionAll1"."C17" AS "C17"
"UnionAll1"."C18" AS "C18"
"UnionAll1"."C19" AS "C19"
"UnionAll1"."C20" AS "C20"
"UnionAll1"."C21" AS "C21"
"UnionAll1"."C22" AS "C22"
FROM
(SELECT
"Except1"."Id" AS "C1"
"Except1"."ManagerId" AS "C2"
"Except1"."AssignedId" AS "C3"
"Except1"."ComplaintTypeId" AS "C4"
"Except1"."RootCauseId" AS "C5"
"Except1"."StatusId" AS "C6"
"Except1"."ResultingFromId" AS "C7"
"Except1"."RespParty" AS "C8"
"Except1"."Condition" AS "C9"
"Except1"."Containment" AS "C10"
"Except1"."CorrectiveAction" AS "C11"
"Except1"."ProductRejected" AS "C12"
"Except1"."IssueDate" AS "C13"
"Except1"."DueDate" AS "C14"
"Except1"."Approved" AS "C15"
"Except1"."ApprovedById" AS "C16"
"Except1"."ApprovedDate" AS "C17"
"Except1"."RejectionDetail" AS "C18"
"Except1"."Parent" AS "C19"
"Except1"."ParentId" AS "C20"
"Except1"."CreatedDate" AS "C21"
"Except1"."CreatedId" AS "C22"
FROM
(SELECT
"Extent1"."Id" AS "Id",
"Extent1"."ManagerId" AS "ManagerId",
"Extent1"."AssignedId" AS "AssignedId",
"Extent1"."ComplaintTypeId" AS "ComplaintTypeId",
"Extent1"."RootCauseId" AS "RootCauseId",
"Extent1"."StatusId" AS "StatusId",
"Extent1"."ResultingFromId" AS "ResultingFromId",
"Extent1"."RespParty" AS "RespParty",
"Extent1"."Condition" AS "Condition",
"Extent1"."Containment" AS "Containment",
"Extent1"."CorrectiveAction" AS "CorrectiveAction",
"Extent1"."ProductRejected" AS "ProductRejected",
"Extent1"."IssueDate" AS "IssueDate",
"Extent1"."DueDate" AS "DueDate",
"Extent1"."Approved" AS "Approved",
"Extent1"."ApprovedById" AS "ApprovedById",
"Extent1"."ApprovedDate" AS "ApprovedDate",
"Extent1"."RejectionDetail" AS "RejectionDetail",
"Extent1"."Parent" AS "Parent",
"Extent1"."ParentId" AS "ParentId",
"Extent1"."CreatedDate" AS "CreatedDate",
"Extent1"."CreatedId" AS "CreatedId"
FROM
"dbo"."CorrectiveActionRequest" AS "Extent1"
WHERE
"Extent1"."ParentId" IS NULL
EXCEPT
SELECT
"Extent2"."Id" AS "Id",
"Extent2"."ManagerId" AS "ManagerId",
"Extent2"."AssignedId" AS "AssignedId",
"Extent2"."ComplaintTypeId" AS "ComplaintTypeId",
"Extent2"."RootCauseId" AS "RootCauseId",
"Extent2"."StatusId" AS "StatusId",
"Extent2"."ResultingFromId" AS "ResultingFromId",
"Extent2"."RespParty" AS "RespParty",
"Extent2"."Condition" AS "Condition",
"Extent2"."Containment" AS "Containment",
"Extent2"."CorrectiveAction" AS "CorrectiveAction",
"Extent2"."ProductRejected" AS "ProductRejected",
"Extent2"."IssueDate" AS "IssueDate",
"Extent2"."DueDate" AS "DueDate",
"Extent2"."Approved" AS "Approved",
"Extent2"."ApprovedById" AS "ApprovedById",
"Extent2"."ApprovedDate" AS "ApprovedDate",
"Extent2"."RejectionDetail" AS "RejectionDetail",
"Extent2"."Parent" AS "Parent",
"Extent2"."ParentId" AS "ParentId",
"Extent2"."CreatedDate" AS "CreatedDate",
"Extent2"."CreatedId" AS "CreatedId"
FROM
"dbo"."CorrectiveActionRequest" AS "Extent2"
WHERE EXISTS
(SELECT
1 AS "C1"
FROM
"dbo"."CorrectiveActionRequest" AS "Extent3"
WHERE
"Extent3"."ParentId"="Extent2"."Id")) AS "Except1"
UNION ALL
SELECT
"Extent4"."Id" AS "Id",
"Extent4"."ManagerId" AS "ManagerId",
"Extent4"."AssignedId" AS "AssignedId",
"Extent4"."ComplaintTypeId" AS "ComplaintTypeId",
"Extent4"."RootCauseId" AS "RootCauseId",
"Extent4"."StatusId" AS "StatusId",
"Extent4"."ResultingFromId" AS "ResultingFromId",
"Extent4"."RespParty" AS "RespParty",
"Extent4"."Condition" AS "Condition",
"Extent4"."Containment" AS "Containment",
"Extent4"."CorrectiveAction" AS "CorrectiveAction",
"Extent4"."ProductRejected" AS "ProductRejected",
"Extent4"."IssueDate" AS "IssueDate",
"Extent4"."DueDate" AS "DueDate",
"Extent4"."Approved" AS "Approved",
"Extent4"."ApprovedById" AS "ApprovedById",
"Extent4"."ApprovedDate" AS "ApprovedDate",
"Extent4"."RejectionDetail" AS "RejectionDetail",
"Extent4"."Parent" AS "Parent",
"Extent4"."ParentId" AS "ParentId",
"Extent4"."CreatedDate" AS "CreatedDate",
"Extent4"."CreatedId" AS "CreatedId"
FROM
"dbo"."CorrectiveActionRequest" AS "Extent4"
INNER JOIN
(SELECT
"Extent5"."ParentId" AS "K1",
CAST
(max("Extent5"."CreatedDate") AS timestamp) AS "A1"
FROM
"dbo"."CorrectiveActionRequest" AS "Extent5"
WHERE
"Extent5"."ParentId" IS NOT NULL
GROUP BY
"Extent5"."ParentId") AS "GroupBy1"
ON
(("Extent4"."ParentId"="GroupBy1"."K1")
OR
(("Extent4"."ParentId" IS NULL )
AND
("GroupBy1"."K1" IS NULL )))
AND
("Extent4"."CreatedDate"="GroupBy1"."A1")) AS "UnionAll1") AS "Limit1"
ORDER BY "Distinct1"."C7" ASC
OFFSET 0
LIMIT 10
罪魁祸首就在最后：
("Extent4"."CreatedDate"="GroupBy1"."A1")) AS "UnionAll1") AS "Limit1"
ORDER BY "Distinct1"."C7" ASC
OFFSET 0
LIMIT 10
它尝试按Distinct1排序，但生成的SQL查询中的任何其他位置都不存在此类标识符。我一直试图调试这几天，并注意到它取决于我选择排序的内容。例如，按Customer.Name排序将生成一个工作查询。按CreatedDate排序不会。
答案 0 :(得分：3)
这可能意味着LIMIT1。看起来你正在使用MySQL并且MySQL驱动程序有一个bug。我会检查以确保您的驱动程序是最新的，或者提交错误。