小编Ana*_*lem的帖子

using (RapidWorkflowDataContext context = new RapidWorkflowDataContext())
                    {
                        var query = from w in context.WorkflowInstances
                        from c in context.Workflows 
                         where EmpWorkflowIDs.Contains((int)w.ID) && w.CurrentStateID != c.LastStateID
                         select w;

                        return query.ToList();
                    }

我有2个表:工作流和工作流程实例.

用于存储对象的工作流和用于存储实例的workflowInstances.

工作流表:ID,Name,FirstStateID,LastStateID

WorkflowInstances表:ID,Name,WorkflowID,CurrentStateID

如何在linq中编写查询到sql,从WorkflowInstances中选择实例,其中CurrentStateID不等于LastStateID

我的数据库中有一个WorkflowInstances表,其中包含以下字段:ID(int),Name(nvarchar(50),WorkflowID(int),Document(varbinary(MAX))).我想插入一个新的WorkflowInstance,所以我写了这段代码

Stream myStream = openFileDialogDoc.OpenFile();
            if (myStream != null)
            {
                using (myStream)
                {
                    WorkflowInstance w = new WorkflowInstance();

                    byte[] bytes = new byte[myStream.Length];
                    myStream.Read(bytes, 0, (int)myStream.Length);
                    w.ID = repository.WorkflowsRepository.GetMaxIDWokflowInstance() + 1;
                    w.Name = textBoxWorkflowInstanceName.Text;
                    w.CurrentStateID = repository.WorkflowsRepository.GetWorkflowFirstState((int)listBoxMyWorkflows.SelectedValue);
                    w.WorkflowID = (int)listBoxMyWorkflows.SelectedValue;
                    w.CreationDate = System.DateTime.Now.ToString();
                    w.Document = bytes;
                    RapidWorkflowDataContext context = new RapidWorkflowDataContext();
                    context.WorkflowInstances.InsertOnSubmit(w);
                    context.SubmitChanges();
                }
            }

我在第15行遇到错误,错误是:无法将类型'byte []'隐式转换为'System.Data.Linq.Binary'