How to execute SQL Query inside DataSet?

slam Iqbal

I want to execute SQL Query within a Dataset. I don't know how it should be done. I just have some sample Query & sample data.

'test.xml file Contains 3 columns:
'ID, Name, Location
'Sample Values:
''ID, Name, Location
''1, abc, loca
''2, ijk, locb
''3, xyz, locc
''4, uvw, locd
Dim ds As New DataSet
ds.ReadXml("test.xml")

    'Sql Query is: "Select Name fom ??? where ID=1"
    'Is this possible to to retrive the output of that Sql query from test.xml using DataSet? 
    'If DataSet does not support this type of operation then how can I execute that or any other query?

Here Is the test.xml File:

<?xml version="1.0" standalone="yes"?>
<DataSetSchema>
<Tab1>
<ID>1</ID>
<Name>abc</Name>
<Location>loca</Location>
</Tab1>
<Tab1>
<ID>2</ID>
<Name>ijk</Name>
<Location>locb</Location>
</Tab1>
<Tab1>
<ID>3</ID>
<Name>xyz</Name>
<Location>locc</Location>
</Tab1>
<Tab1>
<ID>4</ID>
<Name>uvw</Name>
<Location>locd</Location>
</Tab1>
</DataSetSchema>

Wayne Gaylard

A dataset returns a collection of DataTables, in this case it would only contain one Table. I don't think it is possible to query DataSets using SQL. You would need to iterate through the table until you found an ID matching 1 and retrieve the name. Personally I prefer to use XML literals and LinQ to retrieve data from xml files like this

Dim datatest As XDocument = XDocument.Load("Test.xml")
For Each student In From element In datatest...<Tab1>
If student...<ID>.Value = 1 Then
name = student...<Name>.Value
Exit For
End If
Next
MsgBox(Name)

That makes everything very concise and readable. Hope this helps. Happy Coding

slam Iqbal

Is that only one way to do quering a dataset? I tried Dataset.Select("ID=1") but it is not enought for my requirement. anyway thanks.

DaveAuld

You could always bind the data to a bunch of controls e.g. bindingsource, bindingnavigator and datagridview and then use the FILTER property of the BindingSource, as it acts just like a 'where' clause in SQL.

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modified on Thursday, July 15, 2010 10:10 AM