转换 SQL - 使用 SQL IN 的 Linq

Question

我在下面有这个 sql 查询工作正常。 我想把它转换成LINQ

SELECT DISTINCT TOP (100) PERCENT PersonId, FamilyName, GivenName, MiddleName, CompleteName
 FROM         dbo.MainTable AS a
 WHERE     (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table1
                        WHERE      (PersonId = a.PersonId))) OR
                  (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table2
                        WHERE      (PersonId = a.PersonId))) OR
                  (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table3
                        WHERE      (PersonId = a.PersonId)))
ORDER BY FamilyName

代码尝试

 var Sigids = (from a in db.Table1 select a.PersonId);
 var RecIds = (from a in db.Table2 select a.PersonId);
 var AppIds = (from a in db.Table3 select a.PersonId);
 var signatories = (from p in db.MainTable
                   where (Sigids.Contains(p.PersonId)
                   && RecIds.Contains(p.PersonId)
                   && AppIds.Contains(p.PersonId))
                   select new { CompleteName = p.CompleteName, p.PersonId });

但是只有当 personId 是那 3 个表时才会产生这种结果。 我想在这里实现的是我想显示主表中表 1 - 3 的所有名称。

Answer 1

基于以下 sql 查询中的 where 条件

 WHERE     (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table1
                        WHERE      (PersonId = a.PersonId))) OR
                  (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table2
                        WHERE      (PersonId = a.PersonId))) OR
                  (PersonId IN
                      (SELECT     PersonId
                        FROM          dbo.Table3
                        WHERE      (PersonId = a.PersonId)))

linq 中OR运算符的等效项是| 或|| 而不是&& 。 您的 linq 代码应更改为以下使用| ：

 var Sigids = (from a in db.Table1 select a.PersonId);
 var RecIds = (from a in db.Table2 select a.PersonId);
 var AppIds = (from a in db.Table3 select a.PersonId);
 var signatories = (from p in db.MainTable
                   where (Sigids.Contains(p.PersonId)
                   | RecIds.Contains(p.PersonId)
                   | AppIds.Contains(p.PersonId))
                   select new { CompleteName = p.CompleteName, p.PersonId });

或者像下面一样使用|| ：

 var Sigids = (from a in db.Table1 select a.PersonId);
 var RecIds = (from a in db.Table2 select a.PersonId);
 var AppIds = (from a in db.Table3 select a.PersonId);
 var signatories = (from p in db.MainTable
                   where (Sigids.Contains(p.PersonId)
                   || RecIds.Contains(p.PersonId)
                   || AppIds.Contains(p.PersonId))
                   select new { CompleteName = p.CompleteName, p.PersonId });