c# read DataSet Child tables - c#

<products>
<product id="1">
<photos>
<photo addr="1.jpg" />
</photos>
<parameters>
<parameter name="name" />
</parameters>
</product>
</products>
Hello, I have this xml, I want to get values, like photo addr or parameter name I can't.
in DataGrid I am getting like new table. How to Read this parameters by product id?
foreach (DataTable t in dataSet.Tables)
{
Console.WriteLine(t);
}
I am getting: product, photos, photo, parameters, parameter.
Sorry for my English

OK, you need to use schema inferencing to generate an XSD file, then run xsd.exe to generate the DataSet that you're looking for.
To begin with, the XML you've provided won't work off the bat, because you don't have a root node. I'm taking a wild guess here, but if <products> is the root node, we could reformat your XML to look like this:
<products>
<product id="1">
<photos>
<photo addr="1.jpg" />
</photos>
<parameters>
<parameter name="name1" />
</parameters>
</product>
<product id="2">
<photos>
<photo addr="2.jpg" />
</photos>
<parameters>
<parameter name="name2" />
</parameters>
</product>
</products>
We could then take this XML and infer the XSD from it via the XmlSchemaInference class. When I inferred the schema from the XML above, I got this:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="products">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded" name="product">
<xs:complexType>
<xs:sequence>
<xs:element name="photos">
<xs:complexType>
<xs:sequence>
<xs:element name="photo">
<xs:complexType>
<xs:attribute name="addr" type="xs:string" use="required" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="parameters">
<xs:complexType>
<xs:sequence>
<xs:element name="parameter">
<xs:complexType>
<xs:attribute name="name" type="xs:string" use="required" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="id" type="xs:unsignedByte" use="required" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
I then ran xsd.exe with the /dataset option, which gave me a fully functional DataSet representing the original XML. Populating the dataset and the using the DataSet.GetXml() returns the expected XML result.
Final note: I'm not advocating the use of DataSets over domain objects, etc etc. I just wanted to show you what would be the steps for accomplishing your stated objective.

By default DataSet assumes a schema based on elements, not attributes. You'd need to build an xsd for your data to get DataSet to read that XML correctly.
Due to the way this XML is constructed there's no easy way to read this into a DataSet directly. You'd have to use xsd.exe to generate an xsd file and then hand edit it with appropriate attributes from the msdata namespace. It's a quite painful process.
You coud transform the document to a form which would probably parse correctly into DataSet either by rewriting the XML using LINQ or applying an XslCompiledTransform:
<products>
<product id="1">
<photo addr="1.jpg" />
<parameter name="name" />
</product>
</products>
You could also consider using LINQ to XML on it instead of trying to use a DataSet:
var productsInfo = from product in productsElement.Descendants("product")
from photo in product.Descendants("photo")
from parameter in product.Descendants("parameter")
let id = product.Attribute("id")
let addr = photo.Attribute("addr")
let name = parameter.Attribute("name")
select new { ID = id.Value, Addr = addr.Value, Name = name.Value};
If you're developing a new XML layout rather than working with an existing one, you can create the DataSet first using the designer. Populate it with some dummy data, then you can use WriteXml to get the xsd schema and sample data. To preserve relationshps in the XML ouput be sure to set the Nested property on your Relations to be true (See Nesting DataRelations (ADO.NET)).

Related

When validate XSD against XML getting an error?

I'm trying to validate XSD aginst XML but getting an error
The element 'Table' has incomplete content. List of possible elements expected: 'IP21TAG'.
XML:
<NewDataSet>
<Table>
<SITE>VMD</SITE>
<TANK>65-12-392</TANK>
<SERVICE>HZLPG</SERVICE>
</Table>
<Table>
<SITE>VMD</SITE>
<TANK>65-12-392</TANK>
<SERVICE>HZLPG</SERVICE>
<IP21TAG>BC-BBH-OS-4LI21392</IP21TAG>
</Table>
</NewDataSet>
XSD:
<xs:schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="NewDataSet">
<xs:complexType>
<xs:sequence>
<xs:element name="Table">
<xs:complexType>
<xs:sequence>
<xs:element name="SITE" type="xs:string" />
<xs:element name="PLANT" type="xs:string" />
<xs:element name="TANK" type="xs:string" />
<xs:element name="SERVICE" type="xs:string" />
<xs:element name="IP21TAG" type="xs:string" />
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
Can anyone help me how to solve this?
Thanks in advance.
Obviously, solution is to set minOccurs="0" on elements that are optional.
However, error message in Visual Studio displayes even optional elements in the "possible element name" list, so it is not obvious if you miss minOccurs on an element.
My problem was that ONE element missed the minOccurs="0", and error message listed ALL, approximately 100, elements...
You omit minOccurs in <xs:element> node of your schema, its default is one (see specifications) then if you don't specify that node your XML won't be validated against that schema.
If that node is optional simply change your XSD to reflect that. Here I changed just IP21TAG and PLANT (because they're both not present in your example XML but if others are optional too you should change them accordingly):
<xs:element name="IP21TAG" type="xs:string" minOccurs="0"/>
<xs:element name="PLANT" type="xs:string" minOccurs="0" />
If that element is not optional then to be wrong is your XML, you may - for example - provide an empty string instead of a missing node:
<NewDataSet>
<Table>
<SITE>VMD</SITE>
<TANK>65-12-392</TANK>
<SERVICE>HZLPG</SERVICE>
<IP21TAG></IP21TAG>
<PLANT></PLANT>
</Table>
</NewDataSet>

XML DATASET to be Validated

Hello all i have a scenario where i have
TWO XML FILES
one xml say "Books.xml" will create the schema for DATASET and i will use other XML file to load data into DATASET and all data in 2nd file will be inserted into DATASET
I have done these things but i m stuck at validating XML i want to validate 2nd xml file
means data entered into dataset should be exactly valid according to DATASET schema which will be according to First XML
i have tried it using XSD but i am not sure if XSD will be able to validate TYPE of data say if i have to input number and i have a string in my xml ,it should throw an exception
i have my xml like this
<DATA>
<HISTORY>
<book1>SOmebook</book1>
</HISTORY>
<POETRY>
<book2>Books</book2>
</POETRY>
</DATA>
and i am generating my XSD Using VisualStudio
to validate it im using a method something like this
XmlReaderSettings settings = //dont know exact settings
string data = null;
XmlReader Reader = XmlReader.Create(File.Open("C:\books.XML", FileMode.Open), settings, data);
DataSet ds = new DataSet();
ds.ReadXml(Reader);
Here's a quick example on how you can use a schema to validate. I'm using the shiporder example from W3Schools.
Schema:
<?xml version="1.0" encoding="ISO-8859-1" ?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="shiporder">
<xs:complexType>
<xs:sequence>
<xs:element name="orderperson" type="xs:string"/>
<xs:element name="shipto">
<xs:complexType>
<xs:sequence>
<xs:element name="name" type="xs:string"/>
<xs:element name="address" type="xs:string"/>
<xs:element name="city" type="xs:string"/>
<xs:element name="country" type="xs:string"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="item" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="title" type="xs:string"/>
<xs:element name="note" type="xs:string" minOccurs="0"/>
<xs:element name="quantity" type="xs:positiveInteger"/>
<xs:element name="price" type="xs:decimal"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="orderid" type="xs:string" use="required"/>
</xs:complexType>
</xs:element>
</xs:schema>
XML:
<?xml version="1.0" encoding="ISO-8859-1"?>
<shiporder orderid="889923">
<orderperson>John Smith</orderperson>
<shipto>
<name>Ola Nordmann</name>
<address>Langgt 23</address>
<city>4000 Stavanger</city>
<country>Norway</country>
</shipto>
<item>
<title>Empire Burlesque</title>
<note>Special Edition</note>
<quantity>1</quantity>
<price>10.90</price>
</item>
<item>
<title>Hide your heart</title>
<quantity>1</quantity> <!--Change to "one" to see validation error-->
<price>9.90</price>
</item>
</shiporder>
And here's the validation using Linq2XML:
XDocument document = XDocument.Load("shiporder.xml");
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add("", XmlReader.Create("schema.xsd"));
bool errors = false;
document.Validate(schemas, (o, e) =>
{
Console.WriteLine("Validation error: {0}", e.Message);
errors = true;
});
if (!errors)
{
Console.WriteLine("XML document successfully validated.");
}
else
{
Console.WriteLine("XML document does not validate.");
}
Change the value of of the <quantity> node as mentioned in the comment in order to see how the XML does not validate because of invalid type.

How do you generate xsd namespace prefixes in the resulting output file?

I've gone over multiple topics and solutions that talk specifically about this issue. None have worked or I fail to understand what I am doing wrong.
I would like for the namespace prefixes to accompany the element names in the resulting xml output file.
I'm am using the XSD command with Visual Studio 2008 from the VS Command Prompt
Here's my xsd schema for Trial.xsd
<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="Junk"
targetNamespace="http://www.opengis.net/kml/2.2"
xmlns="http://www.opengis.net/kml/2.2"
xmlns:gx="http://www.google.com/kml/ext/2.2"
xmlns:kml="http://www.opengis.net/kml/2.2"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<xs:import namespace="http://www.google.com/kml/ext/2.2" schemaLocation="TestSchema.xsd" />
<!-- Start LookType -->
<xs:complexType name="LookType">
<xs:sequence>
<xs:element ref="gx:TimeSpan" minOccurs="0" />
<xs:element name="longitude" type="xs:string" />
</xs:sequence>
</xs:complexType>
<!-- End LookType -->
<xs:element name="Te" type="LookType" />
</xs:schema>
Here's my xsd schema for TestSchema.xsd
<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="TestSchema"
targetNamespace="http://www.google.com/kml/ext/2.2"
xmlns="http://www.google.com/kml/ext/2.2"
xmlns:gx="http://www.google.com/kml/ext/2.2"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<xs:element name="TimeSpan" type="gx:GXTimeSpanType" />
<!-- Start GXTimeSpanType -->
<xs:complexType name="GXTimeSpanType">
<xs:sequence>
<xs:element name="begin" type="xs:string" />
<xs:element name="end" type="xs:string" />
</xs:sequence>
</xs:complexType>
<!-- End GXTimeSpanType -->
</xs:schema>
I´m generating the resulting class file Trial.cs by using xsd TestSchema.xsd ./Trial.xsd /c /l:cs /n:T
In a program I assign these junk values and write them to file using XmlDocument, XmlSerializer and FileStream
T.LookType te = new T.LookType();
te.longitude = "34.444";
te.TimeSpan = new T.GXTimeSpanType();
te.TimeSpan.begin = "2010-02-26T20:22:00Z";
te.TimeSpan.end = "2010-02-26T20:23:42Z";
I've excluded the method that saves out the file using XmlDocument, XmlSerializer and FileStream as it is a little thicker then I'd like to post unless that is part of the problem.
This is what I get in the resulting file
<?xml version="1.0" encoding="utf-16"?>
<Te xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.opengis.net/kml/2.2">
<TimeSpan xmlns="http://www.google.com/kml/ext/2.2">
<begin>2010-02-26T20:22:00Z</begin>
<end>2010-02-26T20:23:42Z</end>
</TimeSpan>
<longitude>34.444</longitude>
</Te>
This is what I want in the resulting file. Notice the gx:TimeSpan element and the xmlns:gx namespace definition being added to the main Te element.
<?xml version="1.0" encoding="utf-16"?>
<Te xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.opengis.net/kml/2.2"
xmlns:gx="http://www.google.com/kml/ext/2.2">
<gx:TimeSpan>
<begin>2010-02-26T20:22:00Z</begin>
<end>2010-02-26T20:23:42Z</end>
</gx:TimeSpan>
<longitude>34.444</longitude>
</Te>
It doesn't matter on which element the prefixes are declared on, as long as they're declared before they are used. Any code that doesn't like this is broken.
Perhaps because it doesn't matter, XML Schema has no way to influence on which element the prefixes are declared, or which prefix is used.

Exception when loading partial xml data into xsd dataset

I have the following .xsd code:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" id="MyDataSet">
<xs:element name="Row">
<xs:complexType>
<xs:sequence>
<xs:element name="Number" type="xs:int"/>
<xs:element name="Item" type="xs:string"/>
<xs:element name="Comment" type="xs:string"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
And the following .xml file:
<?xml version="1.0" standalone="yes"?>
<MyDataSet>
<Row>
<Number>1</Number>
<Item>first</Item>
</Row>
</MyDataSet>
Since the "Comment" tag is missing in the xml file, I get an exception when running:
MyDataSet myDataSet = new MyDataSet();
myDataSet.ReadXml(xmlFilePath);
The exception is: "Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints."
How can I define the .xsd to be able to receive partial xml data and fill null or any default value when a tag is missing?
Got it... I needed to add the attribute "Nillable" with the value of "true" to the fields that may not arrive in the xml.

"Invalid XPath selection inside field node. Cannot find .." error while loading a schema into the dataset

I want to add an XML schema(Main.xsd) to a dataset which includes another schema(base.xsd) defining the complex types used in the former one.
The Main.xsd has a block defining xs:unique with selector and field to uniquely define a particular element as the primary key.
Here is the Main.xsd:
<xs:schema id="NewDataSet" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://tempuri.org/Main.xsd" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:msprop="urn:schemas-microsoft-com:xml-msprop" targetNamespace="http://tempuri.org/Main.xsd" attributeFormDefault="unqualified" elementFormDefault="qualified" version="3.0.4 01-07-2011">
<xs:include schemaLocation="base.xsd"/>
<xs:complexType name="Employees">
<xs:sequence>
<xs:element name="EmployeeID" type="UE_SignedInt"/>
</xs:sequence>
</xs:complexType>
<xs:element name="Report" type=" Employees" />
<xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
<xs:complexType>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element ref=" Report " />
</xs:choice>
</xs:complexType>
<xs:unique name="ReportConst" msdata:PrimaryKey="true">
<xs:selector xpath=".//Report" />
<xs:field xpath="EmployeeID" />
</xs:unique>
</xs:element>
</xs:schema>
The type “UE_SignedInt” is defind in the base.xsd which is included in Main.xsd.
Now , when I try to include Main.xsd into a dataset, it throws an error: “Invalid XPath selection inside field node. Cannot find EmployeeID” as EmployeeID uses the type which is defined in the base.xsd.
If I use some basic type like “xs:int” to this element , the loading into the dataset works fine. Could anyone please help me to resolve this issue??
The issue was solved when I modifed the unique block as:
<xs:unique name="ReportConst" msdata:PrimaryKey="true">
<xs:selector xpath="." />
<xs:field xpath="EmployeeID" />
</xs:unique>
You need to specify the namespace of the UE_SignedInt element.
<xs:element name="EmployeeID" type="xxx:UE_SignedInt"/>

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