intid =Convert.ToInt32(cmd.ExecuteScalar()); cmd.CommandText ="insert into sontable(fid,names) values(@id,@names)"; cmd.Parameters.Clear(); cmd.Parameters.Add("@id",SqlDbType.Int).Value = id; cmd.Parameters.Add("@names",SqlDbType.VarChar).Value ="李四A"; cmd.ExecuteNonQuery(); t...
ASP.NET AJAX成为.NET 3.5的一部分,除了包括ASP.NET AJAX 1.0的所有功能外,还集成了WebParts的UpdatePanel,与<asp:menu > and < asp:treeview>这样的控件的ASP.NET AJAX 集成,WCF对JSON的支持,编写JavaScript提供了智能提示的功能。 全新的Web开发新体验 Web设计器提供了分割视图编辑、嵌套母板页、以及强大的CSS...
其最后的结果中有个Order,因为from o in ords.DefaultIfEmpty() 是对 ords组再一次遍历,所以,最后结果中的Order并不是一个集合。但是,如果没有from o in ords.DefaultIfEmpty() 这句,最后的select语句写成select new { e.FirstName, e.LastName, Order = ords }的话,那么Order就是一个集合。 4.投影的Let...
You set the TableName property to the property or field that returns the data collection. For example, you might have a class named Person that contains a property named FavoriteCities that returns an array of string values. In that case, you set the ContextTypeName property to Person and ...
(1);// If the database uses original values for concurrency checks,// the client needs to store them and pass them back to the// middle tier along with the new values when updating data.foreach(varvinproducts) {// Persist to a list<Product> declared at class scope.// Additional ...
but in my actual table I have more than 15 columns. So, i have to list all dt1 columns in select clause because of updating one filed OldSales value with dt2 OldValues In My Application i am getting this in many places so is any easy way to return the data without listing the all ...
OrderByDescending The operator sort values in a descending order orderby ... descending Order By ... Descending ThenBy Executes a secondary sorting in an ascending order orderby , Order By , ThenByDescending Executes a secondary sorting in a descending order orderby , descending Order By , Des...
Local type inference, discussed in Chapter 6, Data and Data Types. Anonymous types, something that is new to Visual Basic in 2008, but also something that I haven't discussed yet. I'll give you the details just after this list. Relaxed delegates, a feature that lets Visual Basic make ed...
In order to make it easier to use, I wrote a simple extension method that works with plain oldIQueryable<T>. And here it is: 1: public static IQueryable<T> Where<T>(this IQueryable<T> query, String restriction, params Object[] values) ...
1. Retrieve the object to be changed from the DataContext Use LINQ to retrieve the category you want to update from your DataContext. LINQ's Single method provides an easy way to do this by taking a lambda expression that returns a single object. In this case, the category (c) whose Nam...