Hmm - unique id is in Binary data - how do I query against it?

Hi - I've got a table in SQL server that has its unique ID field as binary data. I have a gridview displaying data from this table and I have set the datakey of this gridview as that binary data field.

I have a 'Select' ciolumn in my gridview that, when selected, will display more details from the selected record. The problem is, how do I pass the selected id back to sql server bearing in mind that it's binary data? Here's what I'm doing at the moment:

I have a function in my data accsess class that queries the database:

Public Function getDetailsById(ByVal Id As System.Byte) As DataSet

Dim con As New SqlConnection(conStr)
Dim cmd As New SqlCommand("SELECT * FROM tableName WHERE Id=@.Id", con)

cmd.Parameters.Add("@.Id", SqlDbType.Binary)
cmd.Parameters("@.Id").Value = Id

Dim ds As New DataSet
Dim adp As New SqlDataAdapter(cmd)
adp.Fill(ds)

Return ds

End Function

And then I call this function from my page with the gridview using:

Dim da As New myDataAccess
Dim ds As New DataSet
ds = da.getDetailsById(GridView1.SelectedDataKey.Value)

But I get the error:

Conversion from type 'Byte()' to type 'Byte' is not valid.

Any ideas where my data/code is going wrong? I'm not sure how to pass this sort of data around?

Thanks

loydall:

Hi - I've got a table in SQL server that has its unique ID field as binary data.

Not trying to be funny... but making your primary key a binary is where you are going wrong.

I know I've queried off of binary fields before, but I don't have any of that code infront of me now.

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Thanks but it's not my db so I have no control over how the ID is stored...

I've fixed it anyway - I just need to use system.byte() rather than system.byte as a parameter in my function - it obviously needed to treat the data as an array...

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Make sure you're getting the correct records back... I seem to remember that SQL will store a binary as 0x00000047 where .Net will see the same value as 0x47000000.

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You are using the wrong ADO.NET command object, you should use ExecuteScalar. Try the link below for complete sample code from Jeff Prosise Programming .NET. The code is in C# but it shows you the correct way to use ExecuteScalar. Hope this helps.

http://kurinjikumaravel.tripod.com/Asp.Net/AspWintellect.txt

Hierarchical Resultset Sorting

I have a query like this

with TempCTE(id, Name, level, sortcol)
As
(
Select id, Name, 0 as level,
cast(cast( id AS BINARY(4)) as varbinary(100)) sortcol
from Table1
where id = 1

union all

Select id, Name, 0 as level,
cast(sortcol + cast( id AS BINARY(4)) as varbinary(100)) sortcol

from Table1 inner join TempCTE on TempCTE.id = Table1.parentid
)

select * from TempCTE order by sortcol

My problem is I want to sort this hierarchical resultset further on name like

aaa
--aaaa
--bbbb
--cccc
aaaaa
bbbbb
--dddd
aaaaa
bbbbb
bbb
--aaaa
--bbbb

Thanks

You need to basically add the appropriate columns in the ORDER BY clause. Based on your query above, you need to probably do ORDER BY sortcol, name. See below example based on a query using AdventureWorks sample tables:

WITH DirectReports(ManagerID, EmployeeID, EmployeeLevel) AS
(
SELECT ManagerID, EmployeeID, 0 AS EmployeeLevel
FROM HumanResources.Employee
WHERE ManagerID IS NULL
UNION ALL
SELECT e.ManagerID, e.EmployeeID, EmployeeLevel + 1
FROM HumanResources.Employee e
INNER JOIN DirectReports d
ON e.ManagerID = d.EmployeeID
)
SELECT replicate('.', EmployeeLevel* 10) + right(replicate('0', 10) + cast(coalesce(ManagerID, 0) as varchar), 10) as Mgr
FROM DirectReports
ORDER BY EmployeeLevel, ManagerID, EmployeeID;
GO