Linq to XML query nested elements
Question
Hi I have been working on this for two days and I don't know why it doesn't work. I have the following XML
Data = new XDocument(
new XDeclaration("1.0", "utf-8", "yes"),
new XComment("UserData"),
new XElement("Users",
new XElement("user",
new XAttribute("name", "Bugs Bunny"),
new XAttribute("userID", "bbunny"),
new XAttribute("usertype", "Customer"),
new XElement("account",
new XAttribute("accounttype", "checking"),
new XAttribute("actbal", 1000),
new XAttribute("actbaldate", "1/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "1/1/2013"),
new XAttribute("tranAmount", 1000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 1000)))),
new XElement("user",
new XAttribute("name", "Tasmanian Devil"),
new XAttribute("userID", "tdevil"),
new XAttribute("usertype", "Customer"),
new XElement("account",
new XAttribute("accounttype", "checking"),
new XAttribute("actbal", -20),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "1/1/2013"),
new XAttribute("tranAmount", 1000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 1000)),
new XElement("trans",
new XAttribute("tranDate", "2/1/2012"),
new XAttribute("tranAmount", 900),
new XAttribute("trantype", "withdrawal"),
new XAttribute("tranBalance", 100)),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 120),
new XAttribute("trantype", "withdrawal"),
new XAttribute("tranBalance", -20)))),
new XElement("user",
new XAttribute("name", "Sam Sheepdog"),
new XAttribute("userID", "ssheepdog"),
new XAttribute("usertype", "Customer"),
new XElement("account",
new XAttribute("accounttype", "checking"),
new XAttribute("actbal", 1000),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "1/1/2013"),
new XAttribute("tranAmount", 1000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 1000)),
new XElement("trans",
new XAttribute("tranDate", "2/1/2012"),
new XAttribute("tranAmount", 500),
new XAttribute("trantype", "transfer"),
new XAttribute("tranBalance", 500)),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 500),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 1000))),
new XElement("account",
new XAttribute("accounttype", "savings"),
new XAttribute("actbal", 500),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 500),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 500)))),
new XElement("user",
new XAttribute("name", "Elmer J. Fudd"),
new XAttribute("userID", "efudd"),
new XAttribute("usertype", "Customer"),
new XElement("account",
new XAttribute("accounttype", "checking"),
new XAttribute("actbal", 100000),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "1/1/2013"),
new XAttribute("tranAmount", 100000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 100000)),
new XElement("trans",
new XAttribute("tranDate", "2/1/2012"),
new XAttribute("tranAmount", 50000),
new XAttribute("trantype", "transfer"),
new XAttribute("tranBalance", 50000)),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 50000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 100000))),
new XElement("account",
new XAttribute("accounttype", "moneymarket"),
new XAttribute("actbal", 50000),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 50000),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 50000)))),
new XElement("user",
new XAttribute("name", "Ralph Wolf"),
new XAttribute("userID", "rwolf"),
new XAttribute("usertype", "Customer"),
new XElement("account",
new XAttribute("accounttype", "checking"),
new XAttribute("actbal", 200),
new XAttribute("actbaldate", "4/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "1/1/2013"),
new XAttribute("tranAmount", 100),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 100)),
new XElement("trans",
new XAttribute("tranDate", "4/1/2012"),
new XAttribute("tranAmount", 100),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 100))),
new XElement("account",
new XAttribute("accounttype", "savings"),
new XAttribute("actbal", 1000),
new XAttribute("actbaldate", "4/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "3/1/2013"),
new XAttribute("tranAmount", 400),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 400)),
new XElement("trans",
new XAttribute("tranDate", "4/1/2012"),
new XAttribute("tranAmount", 600),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 1000))),
new XElement("account",
new XAttribute("accounttype", "moneymarket"),
new XAttribute("actbal", 500),
new XAttribute("actbaldate", "5/1/2013"),
new XElement("trans",
new XAttribute("tranDate", "5/1/2012"),
new XAttribute("tranAmount", 500),
new XAttribute("trantype", "deposit"),
new XAttribute("tranBalance", 500)))),
));
I don't understand why this won't give me a list of trans for a provided userID == efudd and accounttype = checking. When I call foreach it startsto iterate over the items, But then it just stops and there is nothing found.
IEnumerable<Transaction> userAcctInfo =
from item in Data.Descendants("user")
where (string)item.Attribute("usertype") == "Customer" &&
(string)item.Attribute("userID") == userID
from accts in item.Descendants("account")
where (string)accts.Attribute("accounttype") == account
from trans in item.Descendants("user").Descendants("account").Descendants("trans")
select new Transaction((DateTime)trans.Attribute("tranDate"),
(string)trans.Attribute("trantype"),
(decimal)trans.Attribute("tranAmount"),
(decimal)trans.Attribute("transBalance"));
What am I doing wrong? I have looked at several examples here and i just don't understand.
thanks
1 answers
solution1
0 ACCPTED 2013-08-17 01:29:35
- You have to add
Rootproperty call (orElement("Users")) at the beginning of the query. - You should use
Elementsinstead ofDescendantswhen you know where exactly the element is in tree structure. - Why did you start querying for
transfrom theiteminstead ofaccts, which is already defined there?
That one works and returns 3 items
var userAcctInfo =
from item in Data.Root.Elements("user")
where (string)item.Attribute("usertype") == "Customer" &&
(string)item.Attribute("userID") == userId
from accts in item.Elements("account")
where (string)accts.Attribute("accounttype") == account
from trans in accts.Elements("trans")
select new Transaction((DateTime)trans.Attribute("tranDate"),
(string)trans.Attribute("trantype"),
(decimal)trans.Attribute("tranAmount"),
(decimal)trans.Attribute("tranBalance"));
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