Linq to SQL 在 where 子句中使用 COALESCE 进行查询

Question

我正在尝试将以下 sql 查询转换为 linq 到 sql（对于 entity framework）

  select A.*, B.* from TABLE1 A
                   left join TABLE2 B
                  on A.LocationLoadPositionId = B.FkLocationLoadPositionId
                  where COALESCE(B.UploadStatus,0) = 0

到目前为止我已经做到了：

var positions = (from a in dbContext.TABLE1 join b in dbContext.TABLE2
                   on a.LocationLoadPositionId equals b.FkLocationLoadPositionId into c from d in c.DefaultIfEmpty()
                     where d.UploadStatus == false select new { a, d }).ToList();

由于我的 where 条件，上面的 linq 查询似乎无法正常工作...我为上面的两个查询得到了不同的结果集...我在这里缺少什么？...

Answer 1

类似..

var positions = (from a in dbContext.TABLE1
                 join b in dbContext.TABLE2
                 on a.LocationLoadPositionId equals b.FkLocationLoadPositionId into c
                 let x = d.UploadStatus == 0 //<--- COALESCE
                 from d in c.DefaultIfEmpty()
                 where x == true).ToList();
return query.ToList();

Answer 2

试试这个：

var positions = (from a in dbContext.TABLE1 join b in dbContext.TABLE2
                   on a.LocationLoadPositionId equals b.FkLocationLoadPositionId into c from d in c.DefaultIfEmpty()
                     where d.UploadStatus == false || d == null select new { a, d }).ToList();

Linq to SQL 在 where 子句中使用 COALESCE 进行查询

Linq to SQL query with COALESCE in where clause

entity-framework

linq-to-sql