VB.NET LINQ TO SQL Delete Rows From Database

ADO.NET > LINQ TO SQL > Delete rows from database

DeleteOnSubmit removes entity, but does not disappear from the query results until after SubmitChanges is called. 

Example


C#

var deleteData =
    from details in db.GetDetails
    where details.ID == 1
    select details;

foreach (var detail in deleteData )
{
    db.Details.DeleteOnSubmit(detail);
}

try
{
    db.SubmitChanges();
}
catch (Exception e)
{
}

VB.Net

Dim deleteData = _

    From details In db.GetDetails() _

    Where details.ID = 1 _

    Select details

For Each detail As Detail In deleteData

    db.Details.DeleteOnSubmit(detail)

Next 

Try

    db.SubmitChanges()

Catch ex As Exception

End Try

Check Deny Access File C#

C# > System.Security > AccessControl > AuthorizationRuleCollection 

AuthorizationRuleCollection 

Represents a collection of AuthorizationRule objects.

Example

Check Deny Access File C#

public bool CheckDenyAccessFile(string filePath)

{

       FileSecurity fs = File.GetAccessControl(filePath);

       AuthorizationRuleCollection acl = fs.GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier));

       bool deny = false;

       for (int x = 0; x < acl.Count; x++)

       {

              FileSystemAccessRule currentRule = (FileSystemAccessRule)acl[x];

              AccessControlType accessType = currentRule.AccessControlType;

              if (accessType == AccessControlType.Deny && (currentRule.FileSystemRights & FileSystemRights.ListDirectory) == FileSystemRights.ListDirectory)

                {

                    deny = true;

                    break;

                }

        }

        return deny;

}

Writes lines to text file C#

C# > IO  > FileInfo > CreateText

Writes text a new text file.

Example

Writes lines to text file C#

string path = Path.GetTempFileName();

FileInfo fi = new FileInfo(path);

using (StreamWriter sw = fi.CreateText())

{

      sw.WriteLine("Line1");

      sw.WriteLine("Line2");

      sw.WriteLine("Line3");

      sw.WriteLine("Line4");

}      

FileInfo Class C#

C# > IO  > FileInfo Class

FileInfo

Use this class for working with files: create, open, delete, 

move, rename.

Methods

• CreateText

Properties

• Length

String IsNullOrEmpty C# Example

C# > String > Methods > IsNullOrEmpty

With this method you can test simultaneously test whether a String is null or its value is Empty.

Example

string s = "test";

bool b = String.IsNullOrEmpty(s); // false

           

s = null;

b = String.IsNullOrEmpty(s); // true

           

s = "";

b = String.IsNullOrEmpty(s); // true

s = " ";

b = String.IsNullOrEmpty(s); // false

CONVERT SQL Server Example

SQL Server > Built-in Functions > CONVERT

CONVERT converts an expression of one data type to another.

Example

select CONVERT(nvarchar(30), GETDATE(), 100)

result

Oct 15 2014  9:54AM

Other examples:

How to format date and time

Where keyword generic generic type constraint example C#

C# > Generics > where - generic type constraint

With where keyword you can apply restrictions to the kinds of types that client code can use for type arguments when it instantiates the generics class.

Example

    public class A

    {

    }

    public class B:A

    {

    }

    public class GenericList <T> where T : A

    {

    }

    GenericList<A> lst1 = new GenericList<A>(); // OK

    GenericList<B> lst2 = new GenericList<B>(); // OK B derives from A

    GenericList<int> lst3 = new GenericList<int>(); //Error  1      The type 'int' cannot be used as type parameter 'T' in the generic type or method 'WindowsFormsApplication1.GenericList'. There is no boxing conversion from 'int' to 'WindowsFormsApplication1.A'.