Sql Server - Optional SQL Parameters For Binary File UPSERT
Sep 16, 2010
I'm using a stored procedure to updateinsert data into a table using MERGE. One of the items being inserted is a VarBinary file. Now if I wish to add a new file it's just a case of using ReadAllBytes as below, to remove the file I pass DBNull. Now what if other fields are being updated but the file is not being changed? I want the field to remain untouched unless I'm replacing the file or deleting it as above. I cannot add the file via the parameter again as it may only exist in the database, unless I read it first and write it back which seems pointless. [Code]
View 1 Replies
ADVERTISEMENT
Aug 6, 2010
However, I am wondering if there are any workarounds or plans for incorporating this feature into VB.NET in the future?What I'd like to do:
Public Delegate Function Deserializer(Of T)(ByRef Buffer() As Byte, optional ByRef BufferPosition As Integer = 0) As T
'Implementation of a func that matches the delegate'
Class A
Public Function Deserialize(Byref Buffer() as Byte, optional Byref BufferPosition as integer = 0)
....
In the absence of specifying "optional" inside the actual delegate itself, it'd at least be nice to be able to do it in the function implementation only:
Public Delegate Function Deserializer(Of T)(ByRef Buffer() As Byte, ByRef BufferPosition As Integer) As T
'Implementation of a func that matches the delegate'
Class A
Public Function Deserialize(Byref Buffer() as Byte, optional Byref BufferPosition as integer = 0)
....
At least this second way, the functions for the delegate will always have a value mapped to each parameter, although some may come from the function side and not the calling side.
View 2 Replies
Dec 21, 2010
I tried DbNull.Value but no luck. How do I assign a default value as null to a string parameter that is null in VB.NET? Its litte strange to see that VB does not have anything like plain null as most of the other languages do. Also what is the difference between null and DbNull and Nothing.
View 3 Replies
Aug 9, 2011
What is the standard way to implement optional query parameters in a .NET WinForms application?In other words, only query on a field if the value of a corresponding control is not null.
EDIT: I use a FillBy method which calls a query in my Access database. In the TableAdapter query editor, I just used WHERE (field1 = ?) AND (field2 = ?) ... I just can't find the "hook" to bind form controls to the table adapter query parameters and so that if a form uses the default value to not query on it.
View 2 Replies
Jan 21, 2011
Public Function Foo(ByRef a As AClass, _
Optional ByRef b As BClass = Nothing, _
Optional ByRef c As CClass = Nothing) As XClass
Error : Optional parameters must specify a default value.
View 2 Replies
Jan 12, 2010
I would just like to know why. optional parameters cannot have structure types?
View 4 Replies
Nov 3, 2010
I am interacting with VB code on a different tier, using a client-side c# program. The VB function signature looks like this:
Public Sub toggleExclusion( _
ByVal mouse As Double, _
ByVal study As Integer, _
[Code]....
I get an error saying no overloaded method of toggleExclusion takes 2 arguments?
View 3 Replies
Mar 22, 2011
I have an object, called 'PERSON' This person object has a title, firstName & Surname property as well as many other which are at the moment irrelevant. It also has a read only property called Fullname which concatenates the two or three parameters mentioned above depending on an optional parameter 'withTitles' passed over when you call PERSON.FULLNAME
PERSON.FULLNAME(true) <- Will add titles if there are any
PERSON.FULLNAME(false) <- Will give the name without the title
Public ReadOnly Property FullName(Optional ByVal withTitle As Boolean = False) As String
[Code]...
I get an error: PERSON does not contain a property of 'FullName'. If I change this to any other property that does not take a parameter it works as expected. Now I'm guessing that the binding procedure can't handle optional or mandatory parameters for object properties, is this right? Is there a better way to do it? I thought about looping through the collection to add them manually but that kinda defeats the object of DataBinding!
View 1 Replies
Apr 27, 2011
Is there an equivalent in Java to VB.NET's optional parameters?Also is it possible to switch on anything other than integers in Java?
View 1 Replies
May 27, 2010
Is it possible to make Color variable parameters in custom classes Optional?Everytime I try, it gives me a "Constant expression required" error.[code]
View 2 Replies
Oct 6, 2009
I was familiar with the optional parameters in vb 6 and it made sense given the capabilities of the language but why the heck does VB.Net support optional parameters when there is method overloading? Which one should I use and is there a difference? If there is a difference when should I use each one?
View 4 Replies
Sep 7, 2010
I have a custom Attribute class where the constructor takes one fixed parameter and two optional parameters. It is my understanding that one can supply one or more optional parameters by using 'named parameters' such as this:
Private Sub CallMethod()
Me.OptionalMethod(-1, z:=1)
End Sub
[code]....
Well, I thought, perhaps Attributes don't support named parameters. I know they can behave a little weird (they don't support all types in their arguments for example I think), so I thought little of it.But then... I noticed something else. If you take a look at my code of the attribute class again. Notice that I am using an attribute on that class as well... And what do you know: named parameters. Working just fine... The AttributeUsage attribute has the exact same configuration: one fixed parameter and two optional parameters. I seem to be able to call them using named parameters just fine, where I cannot call my own attribute constructor with named parameters...
View 3 Replies
Jan 12, 2010
Most of our code base is in VB.NET. I'm developing a project in C# that uses a lot of the assemblies from the VB.NET code.There are three relevant classes in VB.NET:
[Code]...
View 3 Replies
Oct 20, 2011
I have a search function de build.We are using pure ASP.NET w VB.NET We have multiple DropDownLists and we're building a search query with whatever was selected in those DDLs. My question is, how can I handle the blank values (unselected dropdownlist values) with the SQL Query ? I'm using AND operators in the query so if anything is blank it'll fail the search. If the dropdownlist has no selected value, i don't want the value to be part of the search. It would be easy to code with just 2-3 parameters, but we're looking thru at least 10 items and doing a SWITCH CASE or multiple IFs would soon become mayhem.
View 1 Replies
Dec 6, 2011
I have an image stored in the database as varbinary(max) When it's read out into a datatable, it's only being displayed as System.Byte[]. I've tried every trick in the book to get the binary in string format so I can write it back to the varbinary column in another database.
View 6 Replies
Sep 11, 2010
I'm trying to save a binary file stored in a SQL database with a SaveDialog, the function RetrieveFile retrieves the specified file from the database as a Byte array, here's what I have so far:
Private Shared Function RetrieveFile(ByVal filename As String) As Byte()
Dim connection As New SqlConnection("Data Source=SERVERSQL2008;Initial Catalog=NorthPole;Integrated Security=True")
Dim command As New SqlCommand("SELECT pcfFile FROM Items WHERE pcfFileName=@Filename", connection)
command.Parameters.AddWithValue("@Filename", filename)
connection.Open()
[Code] .....
Files are saved as "SqlDbType.VarBinary" within the database.
I get: "Index was outside the bounds of the array." on:
Dim retrievedBytes As Long = reader.GetBytes(1, startIndex, buffer, 0, ChunkSize)
The MemoryStream appears to not be retrieving the data yet the SQL syntax is correct.
View 1 Replies
Oct 19, 2011
I just got upgraded from VB6.0 to VB2010. I'm trying to move some of my program functions over and I'm getting an error on the ones where I use optional... Public Function GetFolder(ByRef FTT As String, Optional InitFile As String)
I get the error at the end of the line, after the close par...the error is "optional parameters must specify a default value".
View 3 Replies
Sep 22, 2010
i am trying to read data from a sql 2000 database.one of the fields is defined as datatype:image, Length:16.when I am in SQL management studio and do a select for this one column.[code]when i do a datalength on this field it come up with 2404/My question is, I know this is a numeric field, how do i read this into a vb app and how do I break this down into individual values?
View 2 Replies
May 11, 2009
I know how to insert a new row into a table that has a binary column. But is there any way to update the binary column once that row has been added? So far an exhaustive google search has turned up nothing. Get the current row that I wish to update delete the row that I wish to update Create a new row with the information from the row I wish to update plus the new binary It just doesnt seem very elegant, and I was hoping I could do the same thing with an update statement. Here is the updated code I am using now for reference
[Code]...
View 2 Replies
Jan 11, 2010
I have a jpeg file in my C drive from my vb.net application I want to binary read it and store it in SQL server.
View 1 Replies
Sep 10, 2009
I have a string with Binarydata that is 64bit. I want to store this data into SQlServer database and the column is varbinary(Max).When I pass the string I am getting an error saying string cannot be converted into varbinary.
View 1 Replies
Mar 6, 2010
I am trying to have an optional Date value in one of my sub but since you cant set Date to nothing, this doesn't work. And i cant set it to the Date.minvalue inline.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = Nothing)
End Sub
So, i went and set it to some date in the past.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = #1/1/2001#)
End Sub
what would be the proper way to handle the default value for an optional Date?
View 3 Replies
Oct 16, 2010
I'm trying to execute CREATE USER with a given username (via sql parameter)
exec sp_executesql N'CREATE USER @LoginName
FOR LOGIN @LoginName;',
N'@LoginName varchar(5)', @LoginName='myuser'
Heres the code thats generating the above:
Dim myCommand As SqlCommand = New SqlCommand("CREATE USER @LoginName
FOR LOGIN @LoginName;",
ClassDatabaseConnection.CustomInstance)
[code].....
I get and error:Incorrect syntax near '@LoginName'.I think this is due to the parameters being passed as VarChar causing 'MyUser' rather than MyUser Can I not do this with sql parameters?
View 2 Replies
Apr 17, 2010
i know how to use parameters on INSERT, UPDATE and DELETE into sql server.like:
VBNet
updateCMD = "UPDATE table SET somevalue= @valueparam1 WHERE ID = 2"
Adapter.SelectCommand = New SqlCommand(updateCMD)
[code]....
View 16 Replies
Dec 11, 2010
I have insert a data which is in binary format into sql server database table Column type of table is Image Type. I have to read this column from a XML file,I am able to read but
[Code]...
View 3 Replies
Jan 11, 2011
i need to read binary file and in this file found the string and replace it with other one and save the file afterwords. I found many example to read binary, but to find and replace is for me mistery.
View 3 Replies
Apr 18, 2012
The report sits on the Report Server and requires ONE parameter "GROUPNAME". my code gives me a cast error when I try to set the parameters.
Imports Microsoft.Reporting.webforms
Partial Public Class _Default
Inherits System.Web.UI.Page
[code]....
View 1 Replies
May 4, 2009
I need to write data to a file, preferably in binary format, but I am unaccustomed with the concept. Where's the easiest place to get the basics? I could come here with a specific need, but I'm at the point right now where I am more willing to work within the confines of keeping it simple.
Here's what I know:
1. how to open a new file
2. how to specify the record length
3. how to close the file
Some specific questions:
Does the record length have to be constant throughout the file?
Can I read the nth record without reading the whole file?
View 8 Replies
Sep 13, 2011
I want both the client and server to write and read resp. at a constant rate (which can be configured on the GUI of the client) to the buffer.I am able to send from the client at 150 bytes per packet Now, I should be able to read also at 150 bytes per packet on the server too Since, both are connected through a socket, can we retrieve the socket params (set on the client size, like 150 here) from the server end, using the tcpServer object.Or is it must to send an initial setup packet which tells about these client params and so accordingly the server can continue?
View 1 Replies
Jun 14, 2009
I've gone through about 16 hours and two packs of cigarettes trying to figure this out. First a little background. I was using 6.0 up until 2004 when I went to prison. I'm out now, and trying to relearn the trade, using VS 2005. I'm currently porting some 6.0 code from another project, SpyCast Webcam Studio, into VB 8.0. It's disheartening, to say the least. None of the old built-in subs/functions work anymore, so I have to scour the forums to relearn each and every function.The section I'm doing now takes a snapshot from the webcam (Video API --> PictureBox --> Save as Jpeg), then upens the file to upload it to the server via HTTP POST. I've been using this code in SpyCast for years with no trouble, but I spent many hours trying to piece together the right code to open the binary file to read its contents. I pieced together two methods I found around the forums, one using FileStream() though the code I found wasn't for binary files, even though it said it was, so that code doesn't really work. Method two uses Microsoft.VisualBasic.FileOpen() and works better.
Here's the kicker. By the time I run through the rest of the rigamarole of uploading the file, by the time I read it on the webserver, it's *slightly* corrupted. It's a valid Jpeg, no errors, but the picture looks like when I use to watch the Playboy Channel when I was a kid scrambled with weird colors and whatnot. [code] Each "chunk" is basically one "line" of the file. It looks like a single LineInput() return is the text between two carriage returns. Am I correct? I tested this with a flat text file, and it looks true. However, That one input line returns the text or data with the carriage returns *stripped*! ***?!? =( Fine, I have no problem adding my own vbCrLf to each LineInput(), if I were opening text. but this's binary. A character could be Chr(10) or Chr(13), both of which are removed from the original file contents.So I could very well need to use something other than LineInput(), but I haven't found any other examples on the web using this method.
View 1 Replies
