using System.Linq;
public IEnumerable<Product> GetProductsNamedLike(List<Product> productList, string nameLike)
{
return productList.Where(p => p.Name.Contains(nameLike));
}
// Not using lambda:
public IEnumerable<Product> GetProductsNamedLike(List<Product> productList, string nameLike)
{
IEnumerable<Product> products = from Product p in productList
where p.Name.Contains(nameLike)
select p;
return products;
}
/// <summary>
/// Serializes object with no namespace and no <?xml ... > tag. Returns pure xml of the object
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
internal string SerializeObjectPureXML(Object obj)
{
string serialXML = "";
//Empty namespace
XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
ns.Add("", "");
//Serialize the passed object
XmlSerializer xs = new XmlSerializer(obj.GetType());
StringBuilder sb = new StringBuilder();
using (StringWriter sw = new StringWriter(sb))
{
// set XML writer settings
XmlWriterSettings xwSettings = new XmlWriterSettings();
xwSettings.OmitXmlDeclaration = true;
xwSettings.Indent = true;
xwSettings.CloseOutput = true;
// create xml using the settings
using (XmlWriter xw = XmlWriter.Create(sw, xwSettings))
{
xs.Serialize(xw, obj, ns);
// get the xml and clean up
serialXML = sb.ToString();
xw.Flush();
}
sw.Flush();
}
//
return serialXML;
}
/// <summary>
/// An example to show generic predicates
/// </summary>
[Serializable]
public class myProduct
{
/// <summary>
/// ProductCategory
/// </summary>
public enum ProductCategory
{
General = 1,
Speciality = 2
}
private string _Name = string.Empty,
_ProductID = string.Empty;
private ProductCategory _Category;
public string Name
{
get { return _Name; }
set { _Name = value; }
}
public string ProductID
{
get { return _ProductID; }
set { _ProductID = value; }
}
public ProductCategory Category
{
get { return _Category; }
set { _Category = value; }
}
public myProduct() { }
#region "Predicate for Filters"
/// <summary>
/// Predicate for General Products
/// </summary>
/// <param name="p"></param>
/// <returns></returns>
private static bool GeneralProducts(myProduct p)
{
return (p.Category == myProduct.ProductCategory.General);
}
/// <summary>
/// Predicate for Speciality Products
/// </summary>
/// <param name="p"></param>
/// <returns></returns>
private static bool SpecialityProducts(myProduct p)
{
return (p.Category == myProduct.ProductCategory.Speciality);
}
/// <summary>
/// Filter and return General Products
/// </summary>
/// <param name="productList"></param>
/// <returns></returns>
public static List<myProduct> GetGeneralProducts(List<myProduct> productList)
{
return productList.FindAll(GeneralProducts);
}
/// <summary>
/// Filter and return Speciality Products
/// </summary>
/// <param name="productList"></param>
/// <returns></returns>
public static List<myProduct> GetSpecialityProducts(List<myProduct> productList)
{
return productList.FindAll(SpecialityProducts);
}
#endregion "Predicate for Filters"
/// <summary>
/// Anonymous delegate to filter
/// </summary>
/// <param name="productList"></param>
/// <param name="nameLike"></param>
/// <returns></returns>
public static List<myProduct> GetProductsNamedLike(List<myProduct> productList, string nameLike)
{
return productList.FindAll(delegate(myProduct p) { return p.Name.Contains(nameLike); });
}
}
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font-size: 10px;" align="center">
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</div>
</noscript>
--SQL Server: Top 10 of SomeColumn
Select Top 10 * From myTable Where MyColumn = 'MyCondition' Order By SomeColumn Desc
--Oracle: Top 10 of SomeColumn
Select *
From (Select Row_Number() Over (Partition By 'kigo' Order By SomeColumn Desc) myTops,
Column1, Column2, Column3
From myTable Where MyColumn = 'MyCondition')
Where myTops < 10
--Oracle: Gets you 1% records
Select * From myTable Sample(1)
--SQL Server: Random 10
Select Top 10 * From myTable Where MyColumn = 'MyCondition' order by NewID()
--Oracle: Random 10
Select *
From (Select Row_Number() Over (Partition By 'kigo' Order By dbms_random.Value()) myTops,
Column1, Column2, Column3
From myTable Where MyColumn = 'MyCondition')
Where myTops < 10
Cross-site request forgery, also known as one-click attack or session riding and abbreviated as CSRF or XSRF, is a type of malicious exploit of a website whereby unauthorized commands are transmitted from a user that the website trusts. Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user's browser.
There are many things we could possible do to prevent/minimize such attacks. One of my techniques to handle this problem is by requiring a secret, user-specific token in all form submissions; that way the attacker's site can't put the right token in its submissions. I do this by using Session ID as ViewStateUserKey and I will make sure my master base has it covered.
Sample code snippet could look like:
protected void Page_Init(object sender, EventArgs e)
{
Page.ViewStateUserKey = Session.SessionID;
}
The idea was to generate a unique view state key to each session and thus preventing the attacking sites from hijacking the session.
An interesting side problem:
The above technique has been my standard for all my projects. However, one small site threw an error: Validation of viewstate MAC failed. There's a whole lot of discussions, documents and scenarios why this error occurs. Typically this is an error that's common in load balanced environments where the encryption/decryption among servers use different keys. Read my knol about basic check list on load-balancing with IIS. On a side note, never disable ViewState encryption by setting EnableViewStateMac="false"; it's a bad idea.
Coming back to our XSRF, a little investigation showed my error was due to the new session id being generated for every post back. This particular site doesn't use sessoins and Asp.Net being stateless never initializes a session unless being used. In my case, a new session id was being generated every time and leading to the view state key being different for each postback. A simple fix is to make sure to initialize the session. The above code snippet in such case was changed to:
protected void Page_Init(object sender, EventArgs e)
{
Session["NeedThisToInitialize"] = "Yes";
Page.ViewStateUserKey = Session.SessionID;
}
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