on the internet i saw an MySqlDataReader example.
It was saying something like:
read("products")("amount")
I know you can get data from field "product" from the reader by read("product")
but I didn't understand the second () set.
Nowhere info to be found about it.
Is it invalid syntax or a not documented option?
The .read method is used to advance the cursor forward. You can look up the spec online here: https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldatareader.read%28v=vs.110%29.aspx. I've never seen anything like that syntax myself and certainly the doc doesn't indicate it exists.
If you want to retrieve multiple column values in one go you can use .GetValues(). This will populate an array of objects so depending on what you want to do with the data you may need to cast them after retrieval.
Related
Well, this scenario may be quite familiar but I couldn't find the solution.
Scenario:
I am making a REST API call through tFileFetch and I get a json out of it. I parse it to get paging token and more result through tflowtoiterate. Now if more result is equals true, I have to call the same tFileFetch component to get the new set of json using new pagination result.
I have to loop through tFileFetch until the 'more result' is false.
My approach:
Access token-pagination-tFileFetch_1->JSON->tflowtoIterate->more result=true->IF [moreresult=true]->tFileFetch_2->JSON->tFlowtoIterate->more result=true->tLOOP [moreresult.equals{true)->tFileFetch_2->
After tFileFetch2 I have used tSetGlobalVar to put pagination as common var to pass to tFileFetch2
I am not sure whether this approach is appreciable or not, please suggest any improvements if any?
I have actually covered it by myself. 'code' Add SubJob Ok from tLoop to tFileFetch and add condition in tLoop which say until your condition matches 'more result' is false. Finally added delimited output with append mode
I have a HTML multiple select being used which caused no issue until a selection with a comma was entered. When saving / loading the values are split by ',' into a list. Therefore causing an issue
I have tried to find a way of possibly changing the character that is being used to split the values when the form is posted but came to a dead end.
Would be very grateful if someone has any insight into this.
Thanks in advance.
---Update with Code---
The control is created dynamically
Dim SelectName1 As New HtmlSelect
SelectName1.ID = "SelectName" & id
SelectName1.Name = "SelectName"
SelectName1.Multiple = True
and filled by looping though the values.
For Each value As String In Request.Form(idToFind).Split(",")
If Not IsDBNull(SelectName.Items.FindByValue(value)) Then....
I cannot add any more code than that, Apologies
After updating the question by add code, I think the available options are limited:
Create an extra Javascript method, that stores the selected values in a json object and store it into a hidden input field. I'm not an expert in asp.net, though I'm sure there exists a method to parse json objects from a string.
Create an extra javascript method, that concatinating all values to a String and store it into a hidden input field. With creation of a single string, you can define your own delimiter.
After that, add this extra Javascript mehod to the event onSubmit. Then submit the form and read the value from hidden input field.
P.S. In my eyes the second idea is more simple to create, than the first one. And maybe there are better ways.
I am creating a program in VB.NET which uses an online MySQL database to retrieve certain data. I have now succeeded in connecting and getting some basic stuff out of it. Now, what I want to do is that when an user presses a button it has to update the list. What happens is that the stuff that is already in the database also gets resent and so the list just doubles himself, although it adds the new database value.
How can I make sure that it only adds new values to the list, instead of adding all values from the list again? I have read that you can use the Preserve keyword with arrays, though this isn't an array and neither have I figured out how to convert my data into an array.
Private Sub generateList()
DB.writeQuery("SELECT snacks.ID, snacks.naam, snacks.baktijd FROM snacks")
While DB.DR.Read
ListBox1.Items.Add(DB.DR.Item("naam"))
End While
DB.closeConnection()
End Sub
This is the piece of code I use to generate the list, I reuse this code to refresh the list. As you can see, it uses my own written MySQL class. I know it makes an connection so there is nothing wrong with that.
Any help would be appreciated.
What you will want to do is to clear the ListBox before you reload the list. You can do this like so:
ListBox1.Items.Clear()
Then when you reload the list, the items will not be duplicated.
Looks like you need to clear your listbox before adding the items.
ListBox1.Items.Clear()
Try this my friend:
If Not listBox1.Items.Contains(DB.DR.Item("naam")) Then
ListBox1.Items.Add(DB.DR.Item("naam"))
else
'this item already exists.
end if
I'm designing a data table in Access. I have two columns whose values are something like:
col1: CU001-
col2: 03
and i want to join these two string to form another column's default value like: CU001-03
How can i do this?
And one more question is whether using a string as main key tends to be much slower than a numeric?
I’m fairly sure (but open to correction) that you cant have this kind of thing in access using the default value however you can get the same effect by doing something like this.
If you have an unbound form then you can set the value of your 3rd column before you save it like this presto code
With rst
!YourCol1=”foo”
!YourCol2=”bar”
!YourCol3= !YourCol1 & !YourCol2
.Update
End with
Search on “unbound forms” on google to see full examples of unbound forms, also if you are only using JET to store your data then use DAO over ADO as it will be faster
EDIT
I have not read any books specifically on access but I can strongly recommend a few access websites that have helped me. Here they are in no particular order
http://www.mvps.org/access/
http://www.granite.ab.ca/access/
http://www.lebans.com/
http://allenbrowne.com/tips.html
There are many more out there but they are a good place to start
Each parameter in a URL can have multiple values. How can I separate them? Here's an example:
http://www.example.com/search?queries=cars,phones
So I want to search for 2 different things: cars and phones (this is just a contrived example). The problem is the separator, a comma. A user could enter a comma in the search form as part of their query and then this would get screwed up. I could have 2 separate URL parameters:
http://www.example.com/login?name1=harry&name2=bob
There's no real problem there, in fact I think this is how URLs were designed to handle this situation. But I can't use it in my particular situation. Requires a separate long post to say why... I need to simply separate the values.
My question is basically, is there a URL encodable character or value that can't possibly be entered in a form (textarea or input) which I can use as a separator? Like a null character? Or a non-visible character?
UPDATE: thank you all for your very quick responses. I should've listed the same parameter name example too, but order matters in my case so that wasn't an option either. We solved this by using a %00 URL encoded character (UTF-8 \u0000) as a value separator.
The standard approach to this is to use the same key name twice.
http://www.example.com/search?queries=cars&queries=phones
Most form libraries will allow you to access it as an array automatically. (If you are using PHP (and making use of $_POST/GET and not reinventing the wheel) you will need to change the name to queries[].)
You can give them each the same parameter name.
http://www.example.com/search?query=cars&query=phones
The average server side HTTP API is able to obtain them as an array. As per your question history, you're using JSP/Servlet, so you can use HttpServletRequest#getParameterValues() for this.
String[] queries = request.getParameterValues("query");
Just URL-encode the user input so that their commas become %2C.
Come up with your own separator that is unlikely to get entered in a query. Two underscores '__' for example.
Why not just do something like "||"? Anyone who types that into a search area probably fell asleep on their keyboard :} Then just explode it on the backend.
easiest thing to do would be to use a custom separator like [!!ValSep!!].