Keeping Tables Cached On Server In Project
Mar 7, 2010
I have an ASP.NET project which is a front-end to a database. In addition to the large tables, the DB contains a few small tables to help normalize the larger tables with common values. I have a VB.NET project which loads the smaller tables into memory, using "Shared" (i.e., "static" in C#) member variables, and uses them. I have a call to load the tables in Global.asax - Application_Start. This works for a while. That is, Application_Start runs when I first run my project, loads the cached values, and will correctly keep them in memory for a while.
What I'm seeing (when running my project via Visual Studio 2008 Debugger, hosted locally) is:
A) The Application_Start code will run more than once. Not in a row, but after the user has navigated to some other pages, I'll see (my breakpoint in) another call to initialize the cache, coming form Application_Start. Is it expected?
B) The "Shared" variable that was set to True when the cache was initialized is now False again (which should only happen when the class is first loaded). Similarly, all the data that was chached is no longer present. That is, it looks like VB is unloading all the Shared members. Is this expected?
View 1 Replies
ADVERTISEMENT
Aug 23, 2011
I'm using an Entity Framework context, and sometimes would like to create a transaction so that the client can do multiple changes and then commit/rollback them all together.However, if many changes were made, and SaveChanges() was called multiple times, after which a rollback is called, entities that were commited already, will remain the way they were commited, and would not roll back.Here's how my transaction-relative functions look like:
Public Sub BeginTransaction()
Dim context = HttpContext.Current.GetObjectContext()
If Not context.Connection.State = ConnectionState.Open Then
context.Connection.Open()
End If
[Code]...
Not only does the test fail, but it also leave the ObjectContext in an unstable mode, because it still has invalid changes in it.
View 1 Replies
Jun 15, 2011
Below is an snippet from my project template. I have some classes I want to link to in the project.One of my developers created the template and I copied it to my PC.It seems to work on his, but when I create a new project, instead of keeping the hard coded path the "my documents" gets replaced.I know this is a little cryptic, but I was hoping to flesh the question out with your questions.[code]
View 8 Replies
May 15, 2011
...VB express... I recently got a new computer, and then realized that a text file that I opened and read from in one of my apps was not there anymore.I copied the project from my old computer but forgot about the text file. the project's file pointed to it's folder, and the text file's path was somewhere else Is there a way I can keep a file with a project when it's compiled, and then how do I set the path in the app so that the file is found when I want to read it?
View 12 Replies
Jan 7, 2009
I am about to commence coding (actually recoding) on a project that accesses 100 tables of a database, more to added at later time. About half of the accesses are queries with joins and unions. I am more of a coder to not use wizards such tableAdapter, but code more by other methods. I have read some post of this site that suggest avoiding tableAdapters, not to use them in an Enterprise environmentl, but no reasons. I would like to hear from willing to bend my ear, pro or con.
View 1 Replies
Jul 17, 2011
I am not sure if the above title is suitable for what I mean, but basically my application has a login table with entry U_ID and I have also created another field in my other table which will store this ID from the login table.
What I want to do is, if a user with say U_ID = 1 downloads data and stores it in the
second table I would also for trackable reasons be able to store the U_ID of that user
in the second table so that I would know who downloaded the information.
How can I acheive this and if there are any example then point to them.
View 14 Replies
May 27, 2011
I am trying to delete particular tables routinely from the sys.tables in vb.net. here is code, but it does not work.
[Code]...
View 3 Replies
Dec 7, 2010
Can anyone help me with finding all the table names in SQL Server Compact Edition (.sdf file)?
View 3 Replies
Jun 5, 2011
How can I connect two tables from MS SQL Server 2005 using vb.net 2008?
View 5 Replies
Aug 5, 2010
I have one application create tables in database dynamically during run. Another application need to find all these tables' name in the database. how should in do in vb.net
View 7 Replies
Feb 28, 2011
I have a select query like this. But from the below codes, I cannot update t2.unit_price in the same SqlDataAdapter
My Codes :
Dim MyQuery1 as String="Select t1.item_id,t1,group_id,t2.unit_price from Table1 t1 left outer join Table2 t2 on T1.Item_ID=T2.Item_ID"
Dim DAp1 as SqlDataAdapter,Ds1 as New DataSet
Con.Open()
DataAdapter1=New SqlDataAdapter(MyQuery1,Con)
DataAdapter1.Fill(Ds1)
[Code] .....
From the above codes
Dim Sav1 As String = "insert into table1 .........."
I don't know how to mention table2 also there ?
View 2 Replies
Feb 22, 2012
I have a field in the database that is XML because it represents a class that is used in C#/VB.Net. Problem is after the initial manipulation most, but not all, of themanipulation is done in SQL Server. This means that the XML field is converted on the fly.As we are getting more fields and more records, this operation is getting slow. I think the slow down is the converting all of those fields to other data types.So to speed it up I was thinking of a couple of ways:Have a set of tables that represent the different pieces of the XML data. I would make these tables read only using a trigger on Insert/Update that would reject any changes. My 'main' table with the XML in it when it updates the XML would turn off the triggers, update the tables with the new values then turn the triggers back on.
The only real reason we use the XML is because it's really easy to convert it to the class in C#/VB.Net. But I'm getting the point where I may end up writing a routine that will take all the bits and pieces and convert it to a class and also a function to go the other way (class -> tables).
View 2 Replies
Apr 13, 2012
I have about 4 different tables with the exact same column names. What I would like to do is select the top 4 records out of all of these tables combined ordered by date (as date is one of the columns that they all share).
View 1 Replies
Sep 10, 2011
[Code]...
I have Memberships and Bookings tables in database containing an attribute cust_id which is primary key in Memberships and reference key in Bookings. When i am executing data reader I want it to read cust_id values from membership table but it is reading it from the bookings table.....
[Code]...
View 2 Replies
Apr 19, 2010
I have an off-line project. User uses a laptop to input data off line into local SQL server express. Once connected to domain (on line), local data will sync with remote SQL server using sync framework. (It is done, works fine)One job left:Since another user used another program to update some tables in remote SQL server, such as CUSTOMER, SHIPINFO, my off-line program need to update these new data once connect to domain.Here is what I design in Pseudo (take CUSTOMER as example)
1) In remote SQL server, create a store procedure (sp_customer) to select all CUSTOMERS
2) In application, create a dataset (dst_customer) based on sp_customer
3) Insert all customers data which is in remote SQL server but not in local SQL server based on CUSTOMER_ID
View 2 Replies
Mar 20, 2012
I have two tables as follows:
Customer | Product
------------------
A | Car
A | Bike
A | Boat
[Code].....
If I use a normal JOIN then I get a list of friends for every separate product. I just want the two lists once.
The output lists with '-' need not be table cells, they can be <ul>s.
How can I achieve this? I would like to bind to ASP.net GridView. Should I try to do it all in one query, or use multiple queries and somehow add them both to the same Grid?
Each row actually forms part of a long report. Essentially each row of the report contains Customer ID, a bunch of other fields which match one-to-one with Customer ID, then the two lists for each Customer ID I described. Perhaps I can use a separate query for each list, then manually add each list to the grid on RowDataBound or similar?
View 3 Replies
Jul 26, 2011
I know that the .Contains method on a hashset is fast. My question is what is the best method for getting the hashset data before repetitively using the .Contains method?
I can think of 2 options. Both of these examples would be called in a loop of undetermined length.
1) Call the method that returns the cached hashset directly and use the .Contains method.
IF (GetHashSetMethod.Contains("TESTVALUE") THEN BLAH, BLAH, BLAH...
2) Create a new hashset outside of the loop and load the cached hashset data into it so the method that returns the hashset is only called once, then use the .Contains method.
DIM HashTest AS HASHSET(OF String) = GetHashSetMethod
Then in loop:
if (HashTest.Contains("TESTVALUE") THEN BLAH, BLAH, BLAH...
I have been using method 1. Should I even think about switching to method 2? Is there a 3rd option I haven't even thought of? Does it even matter because the data is cached to begin with?
View 2 Replies
Jun 10, 2010
I have a rather large project that several developers access via MS SourceSafe. The issue at hand is the ToolBox lists many, thirty plus, items that start Cached.(the name that follows Cached is the name of a class or Cyrstal Report in the project. There are also many items listed, they have the same "gear" icon, without the word Cached prefix on the class name.
My question is, how can I get these items out of the ToolBox so they never come back?
View 3 Replies
Jan 17, 2010
Is the size of Lists cached in some way (calculated the first time you call it, and then retained untill some change is made to it), or does it get calculated every time you call the Count property? Same question for arrays.
View 11 Replies
Sep 23, 2009
I've got a very simple data structure. I'm using SQLExpress with Linq2SQL and vb.net
**ParentClass**
parentId
name
[code].....
View 1 Replies
Jan 31, 2012
I've been working on my own web browser for a few years now using the webbrowser control in VB.Net.The following routine allows me to pull images on a web page that are stored in the cache:
Private Function GetCachedURLPath(ByVal lpszUrl
As String)
As Boolean
[code]....
This routine has worked well for me, but there are some pages where it is unable to pull the image from the cache. What discovered is that when a web page host images on a different server than the page hosting server, the images get stored in the cache with the address from the image server instead of the src address listed in the IMG tag. Given that I am using the URL from the src in the IMG tag, the routine fails to provide a return path.In most instances reloading the page puts the image into the cache with the same address as the scr record. It was fairly easy to write a routine that automatically reloaded the page when I could not find the image in cache, but one of the things I want to address in my latest revision is this issue.
I have a routine that allows me to run through all of the URL's for the files stored in the internet cache and using that I can figure out the correct URL for a picture, but this seems to me to be about as cumbersome as reloading the page and can be time consuming if the page has a lot of images.I can cut down on the time if I modify the routine to only run through the list on exceptions, but this just seems inefficient to me, especially since I have to make an assumption about what part of the image URL's are the same. What I'd like to do is to track the sources of the images as the web page is being drawn so that I have a listing of all the real source URL's for the images instead of having to rely on what is referenced in the src attribute.
View 5 Replies
Sep 20, 2011
I have a DropDownList in MVC which grabs a SelectList initialized and populated by a controller. The goal of the specific page that said list resides on is to reply "You have selected option X" immediately to the user without refreshing (using Ajax).The problem I'm running into is that for some odd reason, while the dropdown renders properly and even posts back correctly, any attempts to add new options or modify previous response messages are in vain.
My View:
<script type="text/javascript" src="../../Scripts/MicrosoftAjax.js"></script>
<script type="text/javascript" src="../../Scripts/MicrosoftMvcAjax.js"></script>
[code].....
View 1 Replies
Mar 24, 2010
I have a asp.net web forms app that uses System.Web.Caching.Cache to cache xml data from a number of web services for 2 hours.
webCacheObj.Remove(dataCacheKey)
webCacheObj.Insert(dataCacheKey, dataToCache, Nothing, DateTime.Now.AddHours(2), Nothing)
Every 90 minutes a Microsoft Search Server hits a particular (spider) page which calls the code to put the objects into the cache.The issue i have is that over a period of time, the memory usage of the application grows exponentially. Lets say that in a week, the memory usage of the application pool grows to over 1gb
View 1 Replies
Jan 13, 2012
I have a relatively simple piece of code as follows:
Dim oShow As DataSet = Nothing
Dim cacheKey As String = String.Format("AsyncCacheFor_agenda_{0}", ShowID)
If Not IsNothing(Cache(cacheKey)) Then
[code].....
View 2 Replies
May 7, 2009
I have a program I wrote that copies select files from one remote computer to another.
The set up I for testing is, one computer(a) at home running the program connected to my work's network via VPN and two computers(b,c) at work side by side on the same network. I am trying to copy the files on computer b to computer c, while the program is running on computer a.
The only thing wrong with this is, the files seem to be caching to a temp folder on computer a then going to computer c. When it should be going straight from computer b to computer c. Is there a way to keep the files from trying to cache on the computer running the app?
View 1 Replies
Jun 6, 2010
In an ASP.NET 3.5 VB web app, I successfully manage to cache an object containing several personal details such as name, address, etc. One of the items is CreditNum which I'd like to change in the cache on the fly. Is there a way to access this directly in the cache or do I have to destroy and rebuild the whole object just to change the value of objMemberDetails.CreditNum?The cache is set using:
Public Shared Sub CacheSet(ByVal key As String, ByVal value As Object)
Dim userID As String = HttpContext.Current.User.Identity.Name
HttpContext.Current.Cache(key & "_" & userID) = value
End Sub
View 1 Replies
Jan 9, 2012
i am caching objects, if i make linq queries on cached entities then... will theses queries make database round trip due to lazy loading in Entity framework?
View 1 Replies
Apr 28, 2011
This has been driving me insane all day and I think I have the problem narrowed down, but it just doesn't make sense how it could be happening. I have 2 public shared functions and 2 private shared functions. One provides a list of custom objects and one filters the objects based on some parameters in the function call. Both return List(of custom object). The 2 private shared functions are the predicate functions used in the List(of t).RemoveAll function.
[Code]...
Now, the next time I call the GetItemList function it only returns 50 item objects, not the 100 item objects that it should be returning due to the cache being set! I have verified this in the debugger and by running many, many different tests to see what combinations of parameters may be causing the problem. In my testing, as soon as one of the .RemoveAll functions is used the GetItemList item list will get set to whatever the NarrowItemList function returned.
Even if the cache wasn't being set correctly, shouldn't it just get the data again from the database and return 100 items again? What could I be missing???
View 2 Replies
Jun 29, 2010
I'm writing a program which assists users update passwords for our windows systems and some other applications. Everything is working except when I call the UserPrincipal.Current.ChangePassword command cached credentials are not updated like they are when you change a password using the windows OS password change.
That is: when a remote user who is VPN'd in uses my application to change passwords, when they reboot and VPN is disconnected, they are forced to login to windows using there old password.
Is there a way I can force windows to update the cached credentials to the new password so upon reboot they are able to login using this new password?
View 1 Replies
Aug 18, 2011
Is there a way to work the web browser control for viewing off-line (Cached web pages) only? Is it possible to view cached web pages from IE9 on a web browser control off-line? The reason i am asking this question is because IE9 automatically switches from off-line mode to on-line mode when it cannot find something in the cache by default. For forensic purposes this is not acceptable for these reasons: Active content (Viruses, java script, activex cookies etc)
View 1 Replies
