通过LINQ
我想比较记录的ID =参数的ID
那么我想在同一条记录中设置或更新doc_id。
我在这里写了几行:

public void Fill_WF_Doc(string ID, int doc)
{
    DataClasses1DataContext DB = new DataClasses1DataContext();
    Waiting_Task entry = new Waiting_Task();
    var c = from D in DB.Waiting_Tasks
            where (D.WF_ID == ID)
            select D.Doc_ID;
    c = doc;
 }

Cannot implicitly convert type 'int' to 'System.Linq.IQueryable'

最佳答案

通过不对查询调用GetEnumerator的调用，实际上并没有从数据库中检索任何内容。将查询换成()并使用ToList()，First()，Single()或其他查询来调用查询。

Waiting_Task entry = (from D in DB.Waiting_Tasks
                      where (D.WF_ID == ID)
                      select D).FirstOrDefault();

I want set or update the doc_id in the same record.

public void Fill_WF_Doc(string ID, int doc)
{
  DataClasses1DataContext DB = new DataClasses1DataContext();
  Waiting_Task entry = (from D in DB.Waiting_Tasks
                        where (D.WF_ID == ID)
                        select D).FirstOrDefault();
  entry.Doc_ID = doc;

  DB.SubmitChanges();
}

https://stackoverflow.com/questions/7203781/