ADO.NET :: Is It Possible To Save "Collections" To A Single Varbinary(MAX) Field/column In A SQL Server 2008
Oct 9, 2010
I was thinking about the fastest way to retrieve a "set" of objects related to a specific user. For instance, if I was to create a website similar to Flickr where people upload lots and lots of photos(jpegs) what would be the fastest way to be able to retrieve those photos from the SQL Server database. Scenario 1: You store metadata about each file they upload to the website as a single row in a database table. Then when you want to retrieve a specific users uploaded files you simply scan the database file for every row matching the UserID and store them in memory.
This, of course, gets all the information about all the photos a single user has uploaded. My concern with this approach is when the user activity goes from a few thousand to being in excess of a million.
This approach seems fine for a small website but does this method work for a million plus user website like Flicker or MySpace? When you have a million users and millions more photos does this approach still perform at acceptable speeds?
create a collection in memory of "ALL" the PictureIds' for a single user and store them in-memory, in a collection and then save this collection as a single VARBINARY(MAX) field in the SQL Server Database. So instead of having to find multiple records in the Photos database you would simply need to find one, which would include all the PhotoIds' that belong to the user. In essence, translating into the phrase, "If you find one, you have found them all". And improving server performance by leaps and bounds. I only have about a year experience in working with SQL Server and ASP.NET so Im not sure if this solution is practical, if its already been tried, if it can be done.
byte[] a = HashEncrypt("a"); with public byte[] HashEncrypt(string password) { SHA512Managed sha = new SHA512Managed(); byte[] hash = sha.ComputeHash(UnicodeEncoding.Unicode.GetBytes(password)); return hash; }
I want to save byte[] a to my database. My database field is a varbinary(64). I'm using SQL Server 2008. I want to know the insert query with C# code. I am using ADO.NET
I have a function that will take a file uploaded by a user of my system and store the contents of the file into a varbinary(max) field in a sql server database. I then display the filename of the file in a data grid for the user to see as a link button. When the user clicks on the link button, I want the file to be read from the database and served out to the user as a prompt to download the file. How can this be accomplished? The upload is fine, it is the download I can't figure out. Here is what I have so far.
[Code]....
I get the download to prompt, but it is showing the name of my .aspx page as the file to be downloaded.
i want to pass null value into varbinary(max) column n to by table
if i do like this i have this function in my app_code .vb class
Public Function Remove_Attachment(ByVal Id As Integer) As Integer Try Dim db As New dbAccess db.commandText = "SP_RemoveAtt_DML" db.commandType = CommandType.StoredProcedure db.addParameter("@InOutVal_Id", Id) db.addParameter("@Document", System.Data.SqlTypes.SqlBinary.Null.Value) db.executeQuery() Catch ex As Exception Throw ex End Try End Function
i got this error. Data is Null. This method or property cannot be called on Null values.
I have a column in a table that contains a message and I want this message to be displayed in a label. Here is my code which currently doesn't populate the label.
Protected conString As String = ConfigurationManager.AppSettings("sqldirectory") Dim cnn As New SqlConnection(conString) Dim cmd As New SqlCommand("select message from [database].[dbo].[table]") Dim dr As SqlDataReader Try cnn.Open() dr = cmd.ExecuteReader() lblMsg.Text = dr(0).ToString Catch ex As Exception dr = Nothing Finally cnn.Close() End Try
I have a form with many form fields and controls, with some offering an "other" if a value does not meet the needs for the user. How can I bind the sql insert so that it will take the ddl selection along with the txt field selection for the "other" value? Even if the txt field is empty it should not be a big deal since the ddl would provide something other than null. Since the column in the db does not allow nulls. I'm using asp.net (vb) 3.5 sp1
I would like to know if there is a way that I can use DISTINCT on one column's values but need to show other columns where the value of the DISTINCT column is equal to another table's column
I am using below query to count a particular column data based on single condition.
[code].....
But I have to calculate for 3 more conditions. Is it possible to count based on 3 conditions(i.e. 2001 - 3000,3001 - 4000, 4001 - 5000,>5000) and I want result set for all the conditions?
I use a ntext data type for all kind of data save in one field, but when i save byte (that converted from image) follwing message is shown "Operand type clash: varbinary(max) is incompatible with ntext". Is ntext suitable for all kind of data type or what will be compatible for all data type support?
I have some code that allows users to upload file attachments into a varbinary(max) column in SQL Server from their web browser. It has been working perfectly fine for almost two years, but all of a sudden it stopped working. And it stopped working on only the production database server -- it still works fine on the development server.
I can only conclude that the code is fine and there is something up with the instance of SQL Server itself. But I have no idea how to isolate the problem.
I insert a record into the ATTACHMENT table, only inserting non-binary data like the title and the content type, and then chunk-upload the uploaded file using the following code:
i am facing the following problem while saving the viewstate on the server side using the savepagestatetopersistencemedium, but this is not working for the pages which contains update panel.
Implicit conversion from data type sql_variant to varbinary is not allowed. Use the CONVERT function to run this query.
Description:
An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException: Implicit conversion from data type sql_variant to varbinary is not allowed. Use the CONVERT function to run this query.
I create a table in SQL server 2008 and add some colume
after sometime i need to change some properties of colume
but problem come when saveing the table. Error message shown:-
Saving changes are not permitted.the changes you have made required the table to be droped and re-created .you have either made changes to a table that can't be re-created or enabled the option prevent saving changes that required the table to be re-created.
I have a table in sql having a numeric data type column,Now i want that whenever user left this field blank from front end aspx page, null value should be inserted in this column from stored proc.How can i achieve this? Also what kind of data type is most appropriate on front end for such taking kind of value?
