DELETEFROM[TableName]WHEREEXISTS(select..from[TableName]wherequery ); 直接上Code: 代码 调用方式就很简单了,一个Lamdam表达式,就搞定。比如 Console.Write( DataContext.test.Delete(t => t.id != null||t.name.Contains("qq")&&t.Orders.OrderDate<=DateTime.Now)); 例子没有从重写Linq或者扩展Linq表...
发现删除的速度极其缓慢,并且多了许多无用功(取出需要删除元素的列表),在数据量上30万时实在难以忍受 故采用如下方法: ctx.ExecuteCommand("DELETE FROM T_Info_MA WHERE [STOCKCODE]="+stockcode); 若需要清空一个表,则可直接使用: ctx.ExecuteCommand("TRUNCATE TABLE T_Info_MA"); 公告 一眨眼十几年没写...
仅当实体的关联映射将DeleteOnNull设置为true且CanBeNull 为false 时,才会发生推理删除行为。
public static class TableExtension { /// <summary> /// 单表操作批量删除 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="source"></param> /// <param name="query"></param> /// <returns></returns> public static int Delete<T>(this System.Data.Linq.Table<...
cust.Orders.Add(ord)' Delete an existing Order.Dimord0AsOrder= cust.Orders(0)' Removing it from the table also removes it from' the Customer’s list.db.Orders.DeleteOnSubmit(ord0)' Ask the DataContext to save all the changes.db.SubmitChanges() ...
Delete * from my table where ID in (5,9,58,7) If I use LINQ, I have to write var result = from r in db.Role where (r.ID =5) or (r.ID =9) or (r.ID =58) or (r.ID =7) select r; db.Role.DeleteAllOnSubmit(result); ...
1 var result = from Stu in Student 2 where Stu.Address == "南阳" && Stu.Sex == "女" 3 select Stu; 1. 2. 3. View Code 3.排序 orderby子句可以很方便地对返回的数据进行排序。orderby子句对返回的序列中的元素,根据指定的排序类型,使用默认比较器进行排序。其中,ascending表示按顺序排列,为默认...
The only way to actually delete an object is to remove it from its Table collection. C# Copy Customer cust = db.Customers.Single(c => c.CustomerID == custId1); // Pick some order Order o = cust.Orders[0]; // Remove it directly from the table (I want it gone!) db.Orders....
为了在tblMovies数据库表中添加一些记录,请右键单击 Server Explorer 窗口(Visual Web Developer 中的 Database Explorer 窗口)中的tblMovies数据库表,然后选择菜单选项 Show Table Data。使用出现的网格可以插入movie记录(如图 6 所示)。 图6:插入电影(单击查看大图) 向tblMovies表添加若干数据库记录后,再运行应用程...
...111111' WHERE pad like '%0%' " #batch_sql_base = f"DELETE FROM {table_name} WHERE pad like '%0%' " # 确定更新的步长...id 的最小值和最大值 cursor.execute(get_id_range_sql) min_id, max_id = cursor.fetchone() # 按步长循环更新数据...batch_sql) #time.sleep(0.1) # ...