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Diff of 2 tables using vb.net Linq query

I am using an XML file to keep track of files moved, no I want a function to return the files not in both table that match a file pattern.
Both xmaster and xsublist return elements with sub elements, but I don't know how to write a query to return the files not in both tables.

Any help is appreciated.

Public Function FindDiffOfList(ByVal MasterList As String, ByVal SubList As String, ByVal FilePattern As String) As String

        Private XmlDoc As Xml.XmlDocument
        Private sDefXmlPath As String = "C:\...\files.xml"

        XmlDoc.Load(sXmlPath)

        Dim xElmDoc As XElement = XElement.Parse(XmlDoc.ToString)
        Dim xMaster As XElement = xElmDoc.Element(MasterList)
        Dim xSubList As XElement = xElmDoc.Element(SubList)

        Dim Diffs = _
            From nm1 In xMaster.Elements("file") _
                From nm2 In xSubList.Elements("file") _
                Where nm1.Element("name") <> nm2.Element("name") and nm1.Element("name") like FilePattern
            Select nmx

         'Return the filenames as a delimited string ...


    End Function

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Fernando Soto

Hi sidwelle;

Can you post samples of all input files so that the schema of the data can be determined to see if you can use set operators.

sidwelle

ASKER

Attached is an XML that I am testing with.

The code from the post would called like:

dim sList as string = FindDiffOfList("RemoteList", "LocalList", "*.txt")

MsgBox sList
files.xml

Fernando Soto

What would the input variables MasterList and SubList contain for each? Also sXmlPath gets loaded into the variable XmlDoc but what does that file look like?

sidwelle

ASKER

Its attached, let me know if you can't see it.

Thanks
files.xml.txt

ASKER CERTIFIED SOLUTION

Fernando Soto

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sidwelle

ASKER

Ok, let me test and get back to you.
May be Tomorrow before I can get a good test.

Thank You.

sidwelle

ASKER

I get an error 'XPathSelectElements' is not a member of root.
This machine has a copy of VS9, is that too old ?

What version should I have running ?
from my reading, I thought XElement was the preferred object to use because it included the Linq Lib ?

Fernando Soto

Sorry but you need to add this import statement at the top of the file.

Imports System.Xml.XPath

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sidwelle

ASKER

Works, but I have few more questions:
1. Why didn't you use the 'Like' Operator instead of 'EndsWith' ? Does it consume more resources ?
2. I expected the results to be more like a recordset that contained Name, date, size ...
Is this too difficult ?
3 I expected the code to look more like standard SQL, can you do that with XML / Linq ?

Thanks

Fernando Soto

(1) : The Linq to XML provider does not support a Like operator.

(2): In your question you state, "I want a function to return the files not in both table that match a file pattern.", your sample does not show anything else as well. When posting a question you need to be specific enough so that a solution has what you want. To this part of (2), "Is this too difficult ?", not much more difficult but a lot more work.

(3) You only can do what the Linq to XML provider has provided, remember that Linq is a SQL like language and NOT the same language.

sidwelle

ASKER

1.): I swapped it in a it worked (Where (r.Value Like FilePattern) ) ?!
2.): Guess I didn't, just thought the nature of result would contain it.
3.): Can you suggest any good resources that would provide some working examples ? (Besides M.S.)

I always appreciate it when you answer my questions.

Thank You.

Fernando Soto

Not a problem sidwelle, glad to help.