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Hello,
I have an issue with EntityFramework and "set transaction isolation level read uncommitted"
We have changed EF to call a base class (by not using the edmx , this is possible)
In the base class we have overridden the createQuery method to include a call to a SSDL function
<Function Name="Uncommitted" IsComposable="false">
<CommandText>
set transaction isolation level read uncommitted
</CommandText>
</Function>
The reason we do this is so emulate (nolocks) on our sql and thereby help performance of our ASP Web Pages.
This however has brought up a problem.
we have an admin function that has a problem. (DeliveryMethods)
I have a attribute table which is keyed by deliveryMethod and attribute type.
Say I have RowA on that table.
I change and save a value on RowA using an enitiy object in the entityframework.
I then move off to another web page and copy RowA, again using an entity object in entityframework.
The problem is the copy of RowA contains the original values and not the changed ones.
If I do an IIS reset between the amendments and the copy then the new RowA has the changed values so it works ok.
looking at the SQL profiler - The update to the original RowA is
exec sp_executesql N'update [dbo].[DeliveryMethodsRuleAttributes]
set [IntAttribute] = @0, [LastUpdated] = @1, [LastUpdatedBy] = @2
where ([Id] = @3)
',N'@0 int,@1 datetime,@2 nvarchar(4),@3 uniqueidentifier',@0=40000,@1='2009-08-10 17:39:20:383',@2=N'mken',@3='2B60D845-411B-4337-A887-B6BB0F9B9309'
I changed @0 from 30000 to 40000.
The copy process does not issue an SQL Request , so there is no SQL read.
The Copy insert is.
exec sp_executesql N'insert [dbo].[DeliveryMethodsRuleAttributes]([Id], [DeliveryMethodRuleId], [DeliveryMethodId], [AttributeName], [DateTimeAttribute], [IntAttribute], [DecimalAttribute], [TextAttribute], [Created], [CreatedBy], [LastUpdated], [LastUpdatedBy])
values (@0, @1, @2, @3, null, @4, null, null, @5, @6, @7, @8)
',N'@0 uniqueidentifier,@1 uniqueidentifier,@2 uniqueidentifier,@3 nvarchar(14),@4 int,@5 datetime,@6 nvarchar(4),@7 datetime,@8 nvarchar(4)',@0='0264FECD-5EE4-49D3-9CE0-72BAAC11DAA6',@1='722456F0-ACE1-44B0-9568-A03CDD4453C5',@2='053C32B3-808C-4375-9826-02BDC55A8791',@3=N'PriceInCentsTo',@4=30000,@5='2009-08-10 17:42:03:780',@6=N'mken',@7='2009-08-10 17:42:03:780',@8=N'mken'
@4 is set to 30000, which was the original RowA value.
If I deactivate the "set transaction" then this problem does not happen.
Displosing and Closing the EF after the update of RowA has no effect.
Based on the SQL Profile, my theory is that the "uncommited" value is being held in the entityframework and/or underlying ado libraries and this cache is "feeding" the copy of RowA.
My Question is - How do I reset this cache after an update so that the next read uses the SQL DB?
Thanks
Martin
life is a bowl of cherries
go on take a byte
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I am trying to calculate the expiry date for the local user accounts (on a workgroup) using Visual Studio 2008. I can read the last password change date from the "System.DirectoryServices.AccountManagement" namespace but I cannot find a way of reading the maximum password age. I have modified a method for reading this value from a domain (se below) but this returns 'Nothing':
Dim directoryEntry As New DirectoryEntry("WinNT://MyPCName")
strError = directoryEntry.Properties("maxPwdAge").Value
I'm starting to think I'm going about this the wrong way so any ideas would be greatly appreciated.
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if no maximum password age was set by the administrators, I guess such code would return null, or throw an exception for a non-existing field.
Luc Pattyn [Forum Guidelines] [My Articles]
The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
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Thanks for the suggestion but I have already come across a situation like that one when trying to display the account lockout status. There is a maximum password age set (currently and 5 days for test purposes) and passwords do expire after the set number of days..
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dim dr as oledbdatareader
dr = cmd.ExecuteReader()
dr = cmd1.ExecuteReader()
will the execution results be stored in dr.item(0) and dr.item(1) or will the second execution overwrites the first?i tried to add rows with dr.rows.add,but such a thing as addition of rows is not there..i tried executing and i gt the error msg 'Index was outside the bounds of the array'
If i want to execute it will i need to declare seperate data readers for that??
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You definitely need two separate data readers!
EDIT: not sure what you are trying to do exactly, but be aware that data readers are read only.
2+2=5 for very large amounts of 2
(always loved that one hehe!)
modified on Monday, August 10, 2009 1:55 PM
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DataReader is readonly, forward only and for connected use. It means that at time you can access all fields for only one record. Then you need is to more forward and read the next and so until you are done with data. For example
OleDbReader dr = command.ExecuteReader();
while(dr.Read())
{
Cosole.WriteLine(dr[0].ToString());
Cosole.WriteLine(dr[1].ToString());
}
If you want to insert something then DataReader wouldn't help you. You need to write another command and execute it.
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how to implement Filter for listbox using textbox in windows application using vb.net
i have a textbox and a listbox in my application
listbox id binded from database..
now when the user enters anything in textbox the items which starts with the text enterd in the listbox should filter and come in the first
(i mean list box is already filled in ascending order,so only the thing is the scroll should move to the starting of the word which is enterd in the textbox
)
how can i achieve this? any idea?..
(same like the index search in microsoft sites)
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Hi,
I see basically three ways to achieve this:
1.
adapt the database query as you type, using a "LIKE '+myInitialText+"%'" clause. That would be easiest.
2.
adapt the items shown in some other way, maybe by copying them to a list, working on the list, and setting the new list as the new datasource
3.
leaving the items as is, however simply not showing some; that takes DrawMode.OwnerDrawVariable, and returning height zero in MeasureItem for the items you want to hide. (I haven't done this yet, but I think it should work).
Luc Pattyn [Forum Guidelines] [My Articles]
The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
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sorry for the noob question, but i really dont know how to parse down the question to get the answer.
what i am looking for is during setup of an installation program in VS2005 (or newer) how can i have a program added to a users right-click menu for specific file types. an example would be an ISO image burner that i have dl'd and when i right click on an ISO image, the program is present for me to choose.
so, how would i add that to my installation package?
many thanks in advance!
oed
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oedipusrex wrote: how can i have a program added to a users right-click menu for specific file types.
I think you need to add your program in the context menu like the way if you right click on a text file "Notepad" application comes as an option.
You can try out the option mentioned here[^] (thoug i did not get a chance to veify  ).
I found few products are also available [^]which you can add while packaging your installer and obviously it should permit your budget .
Keep me posted if you need any further help.
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Thanks Arindam, I checked out that first link and I understand what he was talking about, however where in my installation package do I add that information? I get the whole merge module business but where or how does that get edited? I have checked the MSDN but either I do not know what to search for or how to phrase my question or simply not experienced enough (on a 4 level scale, I figure myself to be a level 2 programmer...I can code in c++ and vb and a little win32 and put together a simple install package, but that's it) and MSDN only gives a skeleton outline of the process of creating a merge module.
If I have to code it out directly, then that is fine. I am not asking for a direct step-by-step answer, only to be pointed in the right direction. Thanks a million!
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oedipusrex wrote: package do I add that information?
I think probably you understand that you need to have something registry entry for your application (something like below one)
HKEY_CLASSES_ROOT\<file type>\shell\<display text>\command
Now your point is how to do that?
I think this MSDN article[^] might help you.
Keep me posted if this does not help you.
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Is your problem resolved?
Keep me posted on this.
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Dear Developer,
I'm very much concern linq versus stored procedures. can you give an idea where is the best tools to data execution and distribution more faster
TY
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Are you asking how to use stored procedures in Linq to Sql? AFAIK, Entity Framework is replacing Linq to SQL. You should take a look at entity framework rather than learning obsolete framework.
Rolando Y. Puno wrote: where is the best tools to data execution and distribution more faster
What do you mean by that?
IMO, frameworks like Linq to SQL and Entity framework provides a clean abstraction over the data access. It helps you to write maintainable and readable code than giving super fast performance. You get much better performance when you work directly with commands and data readers. My suggestion is to write maintainable code than thinking about performance.
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The SQL generated by EF is sometimes not the best from a performance basis so you may need to use stored procs in conjunction to get the best from it.
only two letters away from being an asset
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Hi I have a service written in Visual C++ 6 that needs to interact with an application written in vb.net. In my service I have used :
<b>DWORD mymsg=RegisterWindowMessage("my_message")</b>
to register a unique custom message.
I then use:
<b>BOOL b=SendNotifyMessage(HWND_BROADCAST,mymsg,NULL,NULL)</b>
to broadcast my message. However, I can't seem to be able to capture this message in the Windowproc function of my vb.net application.
<b>Private Declare Function RegisterWindowMessage Lib "user32" Alias "RegisterWindowMessageA" (ByVal lpString As String) As Integer
Dim mymsg As Integer = RegisterWindowMessage("my_message")
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
if m.Msg=mymsg then
--do something--
end if
end sub</b>
Please help! 
P.S.:I need to show a pop up in my .net application when it receives this message. The message values have all registered properly in both applications and are returned to be the same when I print them. Also the SendNotitfyMessage in my service returns a non zero value(supposed to indicate success). What do I do?? What am I doing wrong? Is there something wrong with my message receiving code in vb.net?
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Try changing your WndProc declaration to:
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub WndProc(ByRef m As Message)
2+2=5 for very large amounts of 2
(always loved that one hehe!)
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Thanks for the suggestion but I tried it and it didn't really work. I don't think it's a security issue. I doubt that.
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Erm I just read your post again and see you are talking about a "service". If you mean a windows system service, then what Mark said is right: you shouldn't be using windows messages to exchange information - follow his advice and use some other form of inter process communications.
2+2=5 for very large amounts of 2
(always loved that one hehe!)
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callousfantom wrote: a service written in Visual C++
A Windows service application? If so, services run in a different desktop
so you may want to use a more suitable IPC mechanism instead of window messages
which don't cross the desktop boundary.
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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Are you trying to say that since the service (SYSTEM acct) is running under a different user context than the application, that the messages won't reach the application from the service? Because my application can communicate via messages with my service using its handle.I've already done that. This implies I can only communicate from the app. to the service and not the other way around. Or does it mean that I can only use handles to communicate one-to-one and broadcasting won't work? Neither of the two seem to make sense to me.
As for another way, I could use custom named events but I've already done one way via messages and I thought I could do the same thing in the other direction.
If there's something else you were trying to suggest then I'm sorry I don't think I quite understood you.
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Hi thanks for all the advice. I've managed to take care of it. I had to make the service interactive in order to make my application visible to it and I found no other way of making it visible due to the different user contexts. So you were right 
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