And if so is there an example in vb .net? I want to add a linq result to the cache and then allow a mvc post to search the cache for better performance...every way I implement it I receive an object not referenced error...
I'm confused, maybe I shouldn't be doing it this way but the mvc post will be checking up to 2000 records and it would seem best not to have it querying the database everytime.
I have created an Entity Model (.edmx) file with MySql database.I added some tables and then try to apply some linq to sql expression but for each expression it thorws an error "Object Reference not set to an instance of the object"
[Code]....
whichever function I call, I get the same error : Object Reference not set to an instance of an object.
I'm not sure why this is, basically when I insert a row using the following function:
[code]....
The field 'Password' ends up having white spaces in it (as in "Password "). So whatever the password is it's trailed by white spaces.
The strange thing is this doesn't happen to the field 'UserName', both are of type char(50).
my table has already 5 rows...after pressing addow, rows are added dynamically to another table... i need to save the data of all the rows(5+newly added) in the database...
View 2 RepliesI would like to be able to send an email notification if a website user inserts a new record in a table. This will be a relatively rare occurrence so it would be very useful to have the notification as opposed to having my users check my summary page that lists all the IDs that have a record in this table. I googled but I must not be hitting on the right keywords or phrase to find the answer to this question. 1) letting me know if this is possible (I'm version ASP.NET 2.0 and using VB with a SQL Server database) and/or 2) pointing me in the right direction to find out how to do it if it is possible.
View 6 Replieshow can i select a record from A table and insert into B table using linq?
View 2 Replies[Code]....
My question is how do i use SqlDataReader to read the last row added to a table getting the contents of a column and storing it as a c# varaible
I have a table in which I have the box amount.How would the table have been added to the + sign.- 10.00 OK, it works.+10.00 - The signs "+" indicatesShows only 10.00 - I do not want to.I would like to table the recorded information +10.00
View 4 Repliesi need to create 2 temporary tables.The records inserted into the 2nd table is the same as that from table1.
Now, i am inserting some other records into table 2.what i need is, to retrieve the count of the recently added records into table2.How to achieve this?
I am exporting some data to a PDF and I have been using iTextSharp with a lot of success, but I just hit a wall.
I have a group of information I need to keep on a single page. This information includes a handful of other Paragraph objects and tables. I can add 3 Paragraphs to another parent Paragraph and set that parent's KeepTogether property to true and everything works great.
When I add a PdfPTable to the Paragraph with KeepTogether set to true, the table disappears. No Exceptions or error messages, the table just disappears.
Any clue as to what is happening? Is there a work around? Should I be coding differently, like is there a better parent control than Paragraph to keep text and tables together on one page?
I need to use caching in my project. The problem is that, When page is firstly load ı cached a dataset. Then after after I update or insert a new record in table. my dataset returns from the cached records.
View 2 RepliesI have been trying to get SqlCacheDependency working. I think I have everything set up correctly, but when I update the table, the item in the Cache isn't invalidated.
I enabled the Service Broker for the Sandbox database.I have placed the following code in the Global.asax file. I also restart IIS to make sure it is called.
void Application_Start(object sender, EventArgs e) {
SqlDependency.Start(ConfigurationManager.ConnectionStrings["SandboxConnectionString"].ConnectionString);
}
I have placed this entry in the web.config file:
<system.web>
<caching>
<sqlCacheDependency enabled="true" pollTime="10000">[code]....
I call this code to put the item into the cache:
protected void CacheDataSetButton_Click(object sender, EventArgs e) {
using (SqlConnection sqlConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["SandboxConnectionString"].ConnectionString))[code].....
Then I bind the GridView with this code:
protected void BindGridViewButton_Click(object sender, EventArgs e) {
if (Cache["Pets"] != null) {
GridView1.DataSource = Cache["Pets"] as DataSet;
GridView1.DataBind();
}
}
Between attempts to DataBind the GridView, I change the table's values expecting it to invalidate the Cache["Pets"] item, but it seems to stay in the Cache indefinitely.
Actually the controls are in a user control on an aspx page that also uses a master page (if that matters)
I defined a table in the skin file with TableHeaderRow, HeaderTableCell. I added some formatting to these entries. The table defined in the control is not being skinned by this definition. If I add a "CssClass" on the TableHeaderCell in the control, the formatting works fine. If I add the CssClass to the skin it doesn't work.
Skin file:
<asp:Table runat="server" SkinID="dataTable" BorderStyle="None" CellPadding="0" CellSpacing="0" CssClass="table">
I have to find the best way to do this using LINQ. I need to summarize an amount in a iTransaction table by
Account (e.g. 12345) and add that amount to an same Account ( e.g12345) if it exists in a iAccount table . Here is the code which syntax checks ok and tested ok up to the .submitChanges statement (i.e. I stopped and didn't allow the submit.
Following is the LINQ code. (1) Is that a good way to do this. OR should I try the INTERCEPT.
(2) How is the best way to insert a new record/row in the iAccounts table if it DOES NOT exist in the iAccount Table.
[Code]....
I have a DataTable with about 10,000 rows in it.
I would like to store this data once for aspx page. When the user selects different options in the page, data is further selected from the already stored DataTable.
I tried using the ViewState, but as soon as the data grows beyond 100 rows, performance degrades.
I creating 3 tier arch wpp in VS 2010. I added the BusinessAccessLayer refernce in Presentation Layer. and I created DataAccessLayer[DAL] and ORM [DBModel.DBML]. when i try to create the instance for the Table in presenation layer[default.aspx], The Table name is not shown.After adding the DataAccessLayer refernce in the presentation layer, the table name[MM_User] instance are shown.Is it the right method [Adding the DAL refernce in Presenation Layer]? If not, whats the solution for for accessing the instance of the tables[MM_User].Is it related to the Creating the DataContextWrapper class in DAL?
View 5 RepliesI am adding table rows dynamically, after I return from a post back, these rows disappear.
Is there a way to preserve these rows and add them back on page load?
I have a question about linq delete.
I have 2 table in database and they are joined.
First Table: UserID, UserName, UserSurname, UserPhone, CompanyId
Second Table: CompanyId, CompanyName
First Table I have many recods with related second table.
I want to delete one company in second record, But firtly I have to delete users (more than 1)
How can I delete it with using linq?
Is it correct to implement my caching object like this in my controller :
[code]....
And I Use it like this :
[code]....
We have a wfc layer that wraps the business classes and database access and use a client that lives on the database layer. Amongst our group we are attempting to form standards. Some want to have the client call the web method and pass the page they are requesting and the page size. Pass that to the database and then page in SQL Server use RowNum.Some want to cache the full list of objects in http cache on the service tier and page in memory. They concern here is memory use on the server.
Which would be best for a medium number of users with potentially large number of records to manage (say 30K) Is it better to cache them all in memory and work from there or page at the database as the application scales?
What are the "optimal" parameters for creating an AppFabric cache when you will be storing session state in the cache? MSDN Cache-Related Commands
Powershell command line:
New-Cache [-CacheName] <String> [-Eviction <String>] [-Expirable <String>] [-Force [<SwitchParameter>]] [-NotificationsEnabled <String>] [-Secondaries <Int32>] [-TimeToLive <Int64>]
[code]...
Since I don't want my sessions to be removed unless the session has been abandoned either via code or Session Timeout...For eviction, I would think "None" and for expireable, I would think False.I have tested and calling Session.Abandon does remove the object from the cache. I have also tested to see if by extending my session, the session object in cache is also extended. This does seem to work the "correct" way.
We have a data driven ASP.NET website which has been written using the standard pattern for data caching (adapted here from MSDN):
public DataTable GetData()
{
string key = "DataTable";
object item = Cache[key] as DataTable;
[code]...
The trouble with this is that the call to GetDataFromSQL() is expensive and the use of the site is fairly high. So every five minutes, when the cache drops, the site becomes very 'sticky' while a lot of requests are waiting for the new data to be retrieved.
What we really want to happen is for the old data to remain current while new data is periodically reloaded in the background. (The fact that someone might therefore see data that is six minutes old isn't a big issue - the data isn't that time sensitive). This is something that I can write myself, but it would be useful to know if any alternative caching engines (I know names like Velocity, memcache) support this kind of scenario. Or am I missing some obvious trick with the standard ASP.NET data cache?
We are using HttpRuntime.Cache API in an ASP.NET to cache data retrieved from a database.
For this particular application, our database queries feature a LOT of parameters, so our cache keys look something like this:
table=table1;param1=somevalue1;param2=somevalue2;param3=somevalue3;param4=somevalue4;param5=somevalue5;param6=somevalue6... etc...
we have so many parameters that the cache key is several hundred characters long. is there a limit to the length of these cache keys? Internally, it is using a dictionary, so theoretically the lookup time should be constant. However, I wonder if we have potential to run into some performance/memory problem.
I have use Nhibernate in my MVC Project by me known, Nhibernate have cache on Session and Object. now, I want use HttpContext.Current.Cache (system.web) for cache data something in project. my code same that have problem, haven't it. and that's right or wrong.
View 2 RepliesI've got a web application that runs of a state server. It looks like soon it may need to distributed and there will be two web servers behind a load balancer.
This works great for session state but my next challenge is Cache
My application leverages heavily of cache. I understand ASP.Net 4.0 will be offering more here but nothing much has been said about the how too.
There are two challenges that I face
1). Each webserver will have its own copy of cache whereas it would be more efficient to put this to a third server the same as session state is put to state server.
2). The real challenge is keeping cache in sync if a simple dataset derived from the database is changed my code dumps that cache item and reloads the cache. That's all well on one webserver but webserver number two wont know to drop that particular cache item and reload it. This could cause some unexpected problems in the application.
For scenario number 2 I could attempt to do some smart coding so server number two knows to dump the cache and reload it.
My guess is someone else has already been here before and there's probably a better implementation approach rather than writing extra code.
Does anyone know how I could achieve the goal of keeping Cache in sync between multiple webservers or even better farm Cache management to another server?
