C# - How To Pull A Random And Unique Record From SQL Via LINQ
Apr 23, 2010
how to pull a RANDOM item from the database when using LINQ. There seems to be a couple of differnet ways to handle this. What I need to do though is pull a RANDOM item from the database that the user has not seen before.
The data I am pulling from the database is very small. Is there any way I can just hit the database once for 1000 records and then randomly scroll through those?
Should I put a cookie on the users system recording the IDs of which items they have seen, pull a random record, check to see if it is seen and if so, pull from the database again? That seems like performance issues just waiting to happen.
Dim RandomNumber As New Random() Dim num As Integer num = RandomNumber.Next(1, 75).ToString Try Dim Cnn As New OleDb.OleDbConnection("File Name=E:WebRHIUDLShelf_Life.UDL;") Dim da As New OleDb.OleDbDataAdapter("SELECT tbMaster_List.dbMFG, tbMaster_List.dbDescription, tbInStock.ID, tbInStock.dbMFG_Lot_Code, tbInStock.dbDateReceived, tbInStock.dbDateOpened, tbInStock.dbExpireDate, tbInStock.dbLocation FROM (tbInStock INNER JOIN tbMaster_List ON tbInStock.LnkToMaster = tbMaster_List.ID) ", Cnn) Cnn.Open() Dim dtt As New DataTable() da.Fill(dtt)
This is were I am stuck.
I need to filter all rows out except where row(index) = num
Me.GridView4.DataSource = dtt Me.GridView4.DataBind() Catch Label1.Text = "Error: Unable to Pull Data" End Try
I want to generate a unique random number everytime a user submits a form. As the form is submited the data of the form should be placed in a database and a unique random number should be generated so that the user can later use this unique random number to reterieve his details from the database that refer to his unique random id. The unique random number should be atleast 9 digits long.
I want to generate a unique random number everytime a user submits a form. As the form is submited the data of the form should be placed in a database and a unique random number should be generated so that the user can later use this unique random number to reterieve his details from the database that refer to his unique random id. The unique random number should be atleast 9 digits long.
I have a form and I want each form to have a unique number when it is filled out so it will go into the database. How can I set this up so when the page loads in the label it will say 1 then the second time it loads it will say 2?
I've build a linq query.But i want a random selection so its not always ID : 1,2,3,4,5,6 How can i randomize this var? I like to bind it to a repeater.//TagCloud:
Random rand = new Random(); var tc1 = from i in JumpTide.cms.menu.GetMenuItems(32) select new
I have location #s, date, time, the sales amount, and tax in a excel file. The system pulls sales numbers throughout the day from each store location and places the total sales and tax numbers along with the polling date into a file.
So the most current date/time has the most upto date sales numbers at the time for that location number, but it also lists the older entries so mgmt can see how sales went during the day, and this is where my issue is, I don't need to see the old numbers from this generated file (atleast at this part of the program).
What I would like to do is write a query that only selects the most recent sales numbers for each location. I will output this to a table in ASP.NET. The query I tried using the TOP 1 clause only gave me the very first row listed below.
I'm trying to select a random record from my database and display the details of the record on screen. The table I am using is the aspnet_Users table which as I'm sure you all know holds the details of users. After a bit of googling, I found the following code:-
[Code]....
I've built my page and I get no errors which is a great start I just can't seem to figure out how to then display the results of this query on the page. I just want to display the username for the record that is selected.
Now I know there is a reason to this odering but my tiny little brain can't get my head around it.I am using a webservice to pull through data to a webp[age and have the following that is so far pulling data through from UUF1:
I am developing a website admin control page....I have to import data from an excel sheet to a table...the table same columns as excel sheet....how do i import data from excel sheet....also i have to make every record unique by giving a unique ID.
I am using a form to add and edit record of database.
In Add case my email box has no value. I have used customservervalidation to check the given email address with previous database records.
In Edit case my email box is populated with data from database.
When i click save button in both cases my customservervalidation method invokes and checks the given value. it works fine for new/add case but in edit case it checks with itself also and says duplicate email... pointing own record...
For context: First of all, I am new to LINQ, as I have been using SubSonic for quite some time now.
I have two tables, Users, and Affiliates. They both have a very typical schema. The FK that joins them is the UserId field, which is in the Affiliates table. I want to create a LINQ query that pulls the Username from the Users table using the AffiliateId value. The AffiliateId is a primary key of the Affiliates table.
I have tried to accomplish this using many variations of the following code:
[Code]....
In the above query, I expect to get a single row result set. However, I instead receive the entire table of results.
How can I make this work? I have yet to see an example or article out there to do what I am trying to do.
I need to pull a SubString from a Linq Datasource, but can't use INTs per .SubString(int, int) I have strings such as xxxx.xxxx.xxxxx.AAAA.xxxx.xxxx.xxxx.xxx and I need to pull AAAA out. the preceeding x's will be varying lengths, so I can't use a static int. What I do know is that there will be a static number of periods (.) leading up to the AAAA. I can't figure out how to use the SubSting with characters rather than indexs. This is what I have so far:
when I insert any character to column Name then A new string random will auto insert into column Random (picture below) I had used Trigger but It was error !
I want to column Random use to code :
DECLARE @myid uniqueidentifier SET @myid = NEWID() insert into table_1 values(@myid, substring(CONVERT(varchar(255), @myid), 1, 5))
but It must auto like column Number (column Number is Identity)
I'm inserting data into a database with Linq to SQL and would like to access the primary key of that record WITHOUT doing a query for the values I've already captured.
Here is my insert startment:
[Code]....
There is a value in the table that is an auto increment integer.
Rather than doing a query for the pagetitle, description and content I'd like to just access the primary key that I would have just generated by performing the insert.
Is this possible or would I have to perform the query as I've just mentioned to retrieve it?
If I have an ID, I would like to retrieve the next item that also has the same category as the item ID I have. So, for example, if I have ID=2, I would like to return the item with ID=4 (as item ID=3 has a different category).
