basic dataadapter/dataset question

[Newbie]

Hi,

I have a dataadapter that contains just a single record.

Dim SqlDataAdapterV alues As New SqlDataAdapter( "select * from
tbl_formatvalue where format_id = " & intFormatInt, dbConnectionIn)
SqlDataAdapterJ obs.Fill(dsForm ats, "formatvalu es")

I want to get the value for column customer_id from this dataset.

usually i would have a dataset with many records, and just do a for each
..... looping through and processing each row.

In this case, as there is only one record in the dataset, is there a better
way to get to the data that using the for each?

Or.. is there a better way of getting my data, is a dataset in this
situation not the best.


Thanks

[sloan]

Re: basic dataadapter/dataset question


DataSets do not do "singles" very well.

If you create a strong dataset.....you can get at the row like this
(sorry I can only do c# from memory)

Let's say I have a strong dataset called OrganizationDS
and I have "Employee" as a table. EmpID (int) adn SSN (string)

OrganizationDS ds = new OrganizationDS( );
ds.Employee.Add NewEmployeeRow ( 101 , "222334444" );

if (null!=ds)
{
if(null!= ds.Employee)
{
if(ds.Employee. Count>0) //<<this might be the Length property
OrganizationDS. EmployeeRow row = ds.Employee[0];
if(null!= row)
{
Console.WriteLi ne ( row.EmpID ) ;
Console.WriteLi ne ( row.SSN ) ;

}

//also use the Select
DataRow[] rows = ds.Employee.Sel ect("EmpID=101" );
if (null!=rows)
{
if(rows.Length> 0)
{
OrganizationDS. EmployeeRow anotherRow = rows[0] as
OrganizationDS. EmployeeRow;
if(null!= anotherRow )
{
Console.WriteLi ne ( anotherRow .EmpID ) ;
Console.WriteLi ne ( anotherRow .SSN ) ;

}

}
}

}
}




Here is a GREAT article on different approaches:
http://msdn.microsoft.com/en-us/library/ms978496.aspx
Bookmark it, read it every 3 months (for 2 years) since you are new.
It wont' "take" the first time, but will make more and more sense as you
develop.

Which is where you will read this:
Passing DataSets As Inputs and Outputs
The disadvantages of this option are as follows:
* Representation of a single business entity


"Newbie" <newbie@nospam. comwrote in message
news:OufnIMvQJH A.1160@TK2MSFTN GP02.phx.gbl...

Hi,
>
I have a dataadapter that contains just a single record.
>
Dim SqlDataAdapterV alues As New SqlDataAdapter( "select * from
tbl_formatvalue where format_id = " & intFormatInt, dbConnectionIn)
SqlDataAdapterJ obs.Fill(dsForm ats, "formatvalu es")
>
I want to get the value for column customer_id from this dataset.
>
usually i would have a dataset with many records, and just do a for each
.... looping through and processing each row.
>
In this case, as there is only one record in the dataset, is there a
better way to get to the data that using the for each?
>
Or.. is there a better way of getting my data, is a dataset in this
situation not the best.
>
>
Thanks
>
>
>

[Rich P]

Re: basic dataadapter/dataset question

Here is how you perform a search on a table in a dataset

Dim drF() As DataRow
drF = dsMain.Tables(" MyTable").Selec t("ID = " & strID)

For Each row As Datarow in drF
console.writeli ne(row("ID").to String & " " & row("Name"))
Next

you can replace the .Select("ID = ...
with .Select("FirstD ate = '" & someStringDate & "'")

The .Select property takes a regular string for the Where part of a sql
statement.

.Select("ID = 1")

.Select("ID = " & someIntVar.ToSt ring)


Rich

*** Sent via Developersdex http://www.developersdex.com ***

[Branco Medeiros]

Re: basic dataadapter/dataset question

Newbie wrote:
<snip>

I have a dataadapter that contains just a single record.
>
Dim SqlDataAdapterV alues As New SqlDataAdapter( "select * from
tbl_formatvalue where format_id = " & intFormatInt, dbConnectionIn)
SqlDataAdapterJ obs.Fill(dsForm ats, "formatvalu es")
>
I want to get the value for column customer_id from this dataset.

<snip>

If you only want one customer_id from the query, you could use the
ExecuteScalar method of the SqlCommand:

<example>
'Prepare the command
Dim Cmd As New SqlCommand( _
"select top 1 customer_id " _
& "from tbl_formatvalue " _
& "where format_id = @format_id")

Cmd.Parameters. Add("@format_id ")
Cmd.Connection = dbConnectionIn

'... elsewhere in your code

'specify the parameter value
Cmd.Parameters( "@format_id").V alue = intFormatInt

'fetch the data ad convert the result to integer
Dim CustID As Integer = Ctype(Cmd.Execu teScalar, Integer)
</example>

Of course, you could build a class to encapsulate all that and have a
method to return the ID already converted to integer and where access
errors etc, would be dealt with...

Dim CustID As Integer = SomeClass.GetCu stomerID(intFor matInt)


Hope this helps.

Regards,

Branco.