linq-to-entities - EF 5 LINQ 在 ON 子句中加入多个条件的表

Question

我正在尝试在 on 子句中使用两个条件连接表，但出现错误

运算符 && 不能应用于 byte 和 byte 类型的操作数

如何在 ON 子句中使用多个条件来连接表？

                    using (var db = new ReleaseInfo())
                {
                    lvReleaseInfo = (from r in db.ReleaseTranslations
                                     join c in db.Countries
                                     on r.SectionRelease.ReleaseCountryID equals c.CountryID && c.CultureID equals CultureID
                                     join pf in db.Platforms
                                     on r.SectionRelease.PlatformID equals pf.PlatformID && pf.PlatformID equals CultureID
                                     join pub in db.Publishers
                                     on r.SectionRelease.PublisherID equals pub.PublisherID && pub.CultureID equals CultureID
                                     where r.ReleaseID == SectionID && r.CultureID == CultureID
                }

Answer 1

您可以为 equi-join 的每一侧创建一个匿名类型：

lvReleaseInfo = (from r in db.ReleaseTranslations
                 join c in db.Countries
                 on new {CountryID = r.SectionRelease.ReleaseCountryID, CultureID} equals new {c.CountryID, c.CultureID}
                 join pf in db.Platforms
                 on new {r.SectionRelease.PlatformID, CultureID} equals new {pf.PlatformID, CultureID = pf.PlatformID}
                 join pub in db.Publishers
                 on new {r.SectionRelease.PublisherID, r.CultureID} equals new {pub.PublisherID, pub.CultureID}
                 where r.ReleaseID == SectionID && r.CultureID == CultureID