c# - How can I combine these linq queries into one? -

-

After being new to LINQ, I have created some questions and want to add them in one, but I'm not sure How do it Here are these: 

  var u = dc.Users.Where (w = & gt; w.UserName == Username) .SingleOrDefault (); Var M = DC. Amberships Where (w = & gt; w.UserId == u.UserId) .SingleOrDefault (); M.PasswordQuestion = Security Question; M.PasswordAnswer = securityAnswer; Dc.SubmitChanges ();

dc.Users is aspnet_Users table
dc.memberhip aspnet_embership table

In addition, SingleOrDefault and FirstOrDefault ?

What is the difference between?

Not sure that they have a relationship (they should). If they do, the linq-to-sql designer will give you a user property on the membership object (or on the other side). Then you can write something like this: 

  var membership = DC Amberships Where (x = & gt; x.User.UserName == Username) .SingleOrDefault ();

If they do not have relationships, then you can write something like this: 

  var membership = (in meters by MCU User is the user equivalent to USISIS, where you select U. Username == Username U). SingleOther Default (); The difference between SingleOrDefault () and FirstOrDefault () is that SingleOrDefault () assumes that there is no one item matching the query. If two items match the query then an exception will be thrown. While you use firstoriflite () and there are two items that match the query, the first will be selected.

Comments

Post a Comment

Popular posts from this blog

php - multilevel menu with multilevel array -

-
Just ask someone to solve this problem? I want to create a multilevel menu I can not find the right solution generated with multilevel array, it always gets an array_push error My study came from the original idea But still my Can not match the need. This is my MySQL [code] ----- --------------------- --------------- | ID | PARENT_ID | Name | Link | Seq | 1 | 0 | Dashboad | Dashboard / | 1 | 2 | 0 | Menu 1 | Menu 1 / | 2 | 3 | 0 | Menu 2 | Menu 2 / | 3 | 4 | 0 | Menu 3 | Menu 3 / | 4 | 5 | 2 | Joint Add / | 1 | 6 | 3 | Joint Add / | 1 | 7 | 2 | Edit | Edit / | 2 | 8 | 4 | Joint Add / | 1 ------------------------------------------ [/ Code] I want to do something like this in my array array ('dashboard' = & gt; array ('id' = & gt; '' 'Dame' = & gt; 'Dashboard', 'Title' = & gt; 'Dashboard', 'MatchMin' = & gt; Base_URL (). 'Dashboard /', 'Active' => = & Gt; NULL), ...
Read more

c# - TypeConverter in propertygrid only converts from string, not to -

-
When the property grid is reached, only the conversion mechanism (often called) is called "Foo!" Returns the property string in the grid when I click to edit I get an exception Type.oo. Object type can not be changed to type. (Not properly translated,) What is a clue from the convert format, why not? And the error indicates that it is trying to convert to a string, not from. I think that when I want to edit this object, it will have to be converted from foo to string, and when the editing ends. Public class FooTypeConverter: StringConverter {public override object ConvertFrom (ITypeDescriptorContext Reference, CultureInfo Culture, Object Value) {New Foo (string) value); } Convert the public override object (Type the ITE DiskText Contact Reference, CultureInfo Culture, Object Value, Type Type) {Return "Foo!"; } Public override bool CanConvertFrom (ITypeDescriptorContext reference, type source type) {back true; } Public Override Bull CanConvertTo (ITypeDescrip...
Read more

jQuery UI: Datepicker month format -

-
I am trying to change the format of the month that shows in the popup (not in the date that the picker actually I do not have any choice anywhere to do this, do I like to use a sub-string () or something else? What I normally display is Trying to change: Class = "ui-datepicker-title"> January & lt; / span & gt; ... & lt; / div & gt; Div>
Read more