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pull individual data element from a datasource? how to?

Author
23 Jan 2006 10:16 PM
simon
Hello
in my codebehind for a user preference form, i instantiate a new
class, and then call a function in that class.  the function calls a
proc which returns a dataset (in this case a single row from the
database with some stored user preferences).  this is all done in the
"Not Page.IsPostBack" IF block, so that is only runs the first time a
page is loaded.

what i'm trying to figure out is how to reference individual data
elements from the returned dataset and then pre-populate the form for
the user (meaning they have already stored their choices)

so what i have in codebehind.vb....

Dim myClass As New DBclass

Dim userPrefs As DataSet =  
    DBclass.GetUserDraftPrefs(Session("groupID"), Session("UserID"))

Dim userPrefCount As Integer = userPrefs.Tables(0).Rows.Count()

If userPrefCount > 0 Then
      here is would want to say something like:
     ddl1.selectedvalue = "the value pulled from the dataset for saved
dropdownlist1"
      and so on for the other form elements
End If

i'm guessing this is pretty straight forward. 
don't know the statement/syntax yet though.  is it like an array where
each "column" in the dataset would be accessed by an index?

thanks for any insight/code-sample !!

Author
23 Jan 2006 11:33 PM
Kerry Moorman
simon,

You could process the single row in the table various ways.

One way:

     Dim dr As DataRow = myDataset.Tables(0).Rows(0)

Now, assuming you have a column named "ID" and it is the first column in the
row, you could refer to it like this:

     dr("ID")

or like this:

     dr(0)

Kerry Moorman


Show quoteHide quote
"simon" wrote:

> Hello
> in my codebehind for a user preference form, i instantiate a new
> class, and then call a function in that class.  the function calls a
> proc which returns a dataset (in this case a single row from the
> database with some stored user preferences).  this is all done in the
> "Not Page.IsPostBack" IF block, so that is only runs the first time a
> page is loaded.
>
> what i'm trying to figure out is how to reference individual data
> elements from the returned dataset and then pre-populate the form for
> the user (meaning they have already stored their choices)

> so what i have in codebehind.vb....
>
> Dim myClass As New DBclass
>
> Dim userPrefs As DataSet =  
>     DBclass.GetUserDraftPrefs(Session("groupID"), Session("UserID"))
>
> Dim userPrefCount As Integer = userPrefs.Tables(0).Rows.Count()
>
> If userPrefCount > 0 Then
>       here is would want to say something like:
>      ddl1.selectedvalue = "the value pulled from the dataset for saved
> dropdownlist1"
>       and so on for the other form elements
> End If
>
> i'm guessing this is pretty straight forward. 
> don't know the statement/syntax yet though.  is it like an array where
> each "column" in the dataset would be accessed by an index?
>
> thanks for any insight/code-sample !!
>
>
Author
23 Jan 2006 11:58 PM
simon
thank you kerry, i believe that is what i'm looking for.  going to try
it out tonight!
out of curiousity, what would another way be to do it?  learning the
language, so i appreciate any and all tips!  take care

Show quoteHide quote
>simon,
>
>You could process the single row in the table various ways.
>
>One way:
>
>     Dim dr As DataRow = myDataset.Tables(0).Rows(0)
>
>Now, assuming you have a column named "ID" and it is the first column in the
>row, you could refer to it like this:
>
>     dr("ID")
>
>or like this:
>
>     dr(0)
>
>Kerry Moorman
>
>
>"simon" wrote:
>
>> Hello
>> in my codebehind for a user preference form, i instantiate a new
>> class, and then call a function in that class.  the function calls a
>> proc which returns a dataset (in this case a single row from the
>> database with some stored user preferences).  this is all done in the
>> "Not Page.IsPostBack" IF block, so that is only runs the first time a
>> page is loaded.
>>
>> what i'm trying to figure out is how to reference individual data
>> elements from the returned dataset and then pre-populate the form for
>> the user (meaning they have already stored their choices)
>> 
>> so what i have in codebehind.vb....
>>
>> Dim myClass As New DBclass
>>
>> Dim userPrefs As DataSet =  
>>     DBclass.GetUserDraftPrefs(Session("groupID"), Session("UserID"))
>>
>> Dim userPrefCount As Integer = userPrefs.Tables(0).Rows.Count()
>>
>> If userPrefCount > 0 Then
>>       here is would want to say something like:
>>      ddl1.selectedvalue = "the value pulled from the dataset for saved
>> dropdownlist1"
>>       and so on for the other form elements
>> End If
>>
>> i'm guessing this is pretty straight forward. 
>> don't know the statement/syntax yet though.  is it like an array where
>> each "column" in the dataset would be accessed by an index?
>>
>> thanks for any insight/code-sample !!