Linq 2 SQL 语法帮助

Question

我几乎完成了将 MySQL 应用程序转换为 Linq2SQL 的工作，但我很难理解最后一个 SQL 查询

SELECT a.URL, b.URL AS DuplicateURL
FROM Pages a
INNER JOIN Pages b ON a.MetaDescription = b.MetaDescription
                   AND a.PageID <> b.PageID
WHERE a.DomainID = @reportid
  AND b.DomainID = @reportid
  AND LENGTH(TRIM(a.MetaDescription)) > 0
  AND a.URL < b.URL
ORDER BY a.URL ASC

能否再给我一些关于如何在 Linq2SQL 中创建此查询的语法帮助？

非常感谢任何帮助

Answer 1

是这样的：

var DuplicatePages = 
    from a in DBContext.Pages
    join b in DBContext.Pages on a.MetaDescription equals b.MetaDescription
    where (a.PageID <> b.PageID) && (a.DomainID == ReportID) && 
    (b.DomainID == ReportID) && (a.MetaDescription.Trim().Length > 0) && 
    (a.URL < b.URL)
    orderby a.URL
    select new { Url = a.URL, DuplicateUrl = b.URL };

Answer 2

这很简单：

var reportId = ...;

var duplicates =
    from a in db.Pages
    from b in db.Pages
    where a.MetaDescription == b.MetaDescription
    where a.PageID != b.PageID
    where a.DomainID == reportId
    where b.DomainID == reportId
    where a.MetaDescription.Trim().Length > 0
    where a.URL < b.URL
    orderby a.URL
    select new { Url = a.URL, DuplicateUrl = b.Url }