求助如何正确使用LINQ join isnull和把查询结果转换成datatable
SQL是下面这样写的,目的是用join比较两个datatable,这两个datatable验证过都是有数据的,筛选条件是其中一个表某个字段是null
select dsGLVRELF.Tables[0].* from dsGLVRELF.Tables[0] abc join dsLKMAsso.Tables[0] xyz on abc.service_tag=xyz.service_tag where xyz.service_tag is null
我自己折腾出来的linq是下面酱紫的,但是,总是提示搜索出来的结果里面没有datarow, 不知道是linq不对,还是把LINQ结果转换成datatable方法不对
var RelfnoAsso = from relief in dsGLVRELF.Tables[0].AsEnumerable()
join associated in dsLKMAsso.Tables[0].AsEnumerable() on relief.Field<string>("SERVICE_TAG") equals associated.Field<string>("SERVICE_TAG")
where associated.Field<string>("SERVICE_TAG") == null
select relief;[/align]
DataTable dtRelfNoAsso = new DataTable();
dtRelfNoAsso = RelfnoAsso.CopyToDataTable<DataRow>(); //source contains no data