Export binary data from database using LINQPAD

Switch LinqPad to c# Program

void Main()
{
    var students = Students.Where(st => st.Photo != null).Select(st => new
    {
        st.Id,
        st.Photo
    });
    foreach (var student in students)
    {
        File.WriteAllBytes(@"D:\Photos\" + student.Id + ".jpg", student.Photo.ToArray());
    }
}

LINQ to Entities does not recognize the method 'System.String PadLeft(Int32)'

Convert to list then do padleft

The entity type List`1 is not part of the model for the current context

where db is List

db.Entry(bd).State = EntityState.Modified;

DbContext.Entry(object) expects a single object, not a collection.
so use a loop instead

foreach (var item in bd)
{
    db.Entry(item).State = EntityState.Modified;
}

Convert dictionary to list collection in C#

using linq

accountTypes.Select(kvp => new
            {
                account_type_no = kvp.Key,
                account_type_name = kvp.Value
            }).ToList()

using loop

foreach (var item in accountTypes)
{
    accountTypeList.Add(item.Key);
}

How to remove all CSS classes using jQuery?

$("#item").removeClass();

How to get schema from stored procedure sql server

ADO.NET

DataTable schema = reader.GetSchemaTable();

SQL

SELECT * FROM sys.dm_exec_describe_first_result_set ('qualified.storedprocname', @params, 0) ;

How to submit / save changes in LinqPad

void Main()
{
    var students = Student.Select(st => st);
    foreach (var student in students)
    {
        student.FatherName = "Father";
    }
    SubmitChanges();
}

How to change a value of a DataItem in a GridViews RowDataBound Event

if (e.Row.RowType == DataControlRowType.DataRow)
{
 DataRow row = ((DataRowView)e.Row.DataItem).Row;
 for (int i = 0; i < row.ItemArray.Length; i++)
 {
  var obj = row.ItemArray[i];
  if (obj.GetType().Name == "DateTime")
  {
   e.Row.Cells[i + 1].Text = ((DateTime)obj).ToShortDateString();
  }
  else if (obj.GetType().Name == "Boolean")
  {
   e.Row.Cells[i + 1].Text = ((Boolean)obj).ToYesNo();
  }
 }
}

jQuery: get the file name selected from

$('input[type=file]')[0].files[0].name;

$("input[type=file]")[0].files[0].type;

$("input[type=file]")[0].files[0].size;

How do you check if a certain index exists in a sql server table?

IF EXISTS(SELECT * FROM sys.indexes WHERE name='[IndexName]' AND object_id = OBJECT_ID('[Schema].[Table]'))
BEGIN
    --statements
END

SET ENABLE SQL Server Broker taking too long time

ALTER DATABASE <db_name>
SET ENABLE_BROKER WITH ROLLBACK IMMEDIATE

How to disable all triggers MS SQL Server

To disable all trigger

sp_msforeachtable 'ALTER TABLE ? DISABLE TRIGGER all'

Or to enable or triggers

sp_msforeachtable 'ALTER TABLE ? ENABLE TRIGGER all'

Enable / Disable trigger in MS SQL server

DISABLE

ALTER TABLE table_name DISABLE TRIGGER tr_name

ENABLE
ALTER TABLE table_name ENABLE TRIGGER tr_name

SQL Server: Database stuck in “Restoring” state

RESTORE DATABASE MyDatabase
FROM DISK = 'MyDatabase.bak'
WITH REPLACE,RECOVERY

LINQ to Entities returning “Object reference not set to an instance of an object.”

EF does not support nullable composite primary keys if your one of the keys is null it will return the exception

How to store string in a cookie and retrieve it

Writing a cookie

HttpCookie myCookie = new HttpCookie("MyTestCookie");
DateTime now = DateTime.Now;
 
// Set the cookie value.
myCookie.Value = now.ToString();
// Set the cookie expiration date.
myCookie.Expires = now.AddYears(50); // For a cookie to effectively never expire
 
// Add the cookie.
Response.Cookies.Add(myCookie);

Reading a cookie

HttpCookie myCookie = Request.Cookies["MyTestCookie"];
 
// Read the cookie information and display it.
if (myCookie != null)
    Response.Write("<p>" + myCookie.Name + "<p>" + myCookie.Value);
else
    Response.Write("not found");

why cookies are always null after postback

private static string GetCookie(string name)
{
    return HttpContext.Current.Request != null ? HttpContext.Current.Request.Cookies[name].Value : string.Empty;
}
 
private static void SetCookie(string name, string value)
{
    HttpContext.Current.Request.Cookies[name].Value = value;
    HttpContext.Current.Request.Cookies[name].Expires = DateTime.Now.AddDays(100);
}

How to check if column exists in SQL Server table

IF EXISTS(SELECT * FROM sys.columns 
WHERE Name = N'columnName' AND Object_ID = Object_ID(qualified.table.name')) 
BEGIN 
    PRINT 'Column Exists'
END
--OR
IF COL_LENGTH('qualified.table.name','column_name') IS NULL
BEGIN
    PRINT 'Column does not exist or caller does not have permission to view the object'
END