Programmatically log in a user, or emulate a user logging in

If you need to log a user on programmatically, that is with no input of password, you can do the following just using their user name:

FormsAuthentication.SetAuthCookie(UserName, True)
Response.Redirect("/somewhere_suitable")

I recently used this to allow a system administrator to login to any user's account as that user by clicking on a button from a list of users. This must be a pretty common thing to do so here's the whole bit of code for the button event:

Protected Sub UsersList_ButtonPress(ByVal sender As Object, ByVal e As ListViewCommandEventArgs) Handles UsersList.ItemCommand

  If e.CommandName = "Login" Then

      Dim userID As Guid = New Guid(e.CommandArgument.ToString)

      Dim user As MembershipUser = Membership.GetUser(userID)
      FormsAuthentication.SetAuthCookie(user.UserName, True)

      Response.Redirect("/somewhere_suitable")

  End If
End Sub

And here's the designer code for the button in the itemtemplate of the listview:

<td>
 <asp:Button ID="LoginButton" runat="server" CommandArgument='<%# Eval("UserID")%>' CommandName="Login" Text="Login" OnClientClick="return confirm('Are you sure you want to login as this user?');" />
</td>

You could of course just send the username as an argument directly from the list, but I didn't do this as the userID just suited some other stuff I've got going on there too!

SQL convert datetime to string

I found this posted on another site. It's Really Useful, so I though I'd replicate it here for next time.

0	Feb 22 2006 4:26PM	CONVERT(CHAR(19), CURRENT_TIMESTAMP, 0)
1	02/22/06	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 1)
2	06.02.22	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 2)
3	22/02/06	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 3)
4	22.02.06	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 4)
5	22-02-06	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 5)
6	22 Feb 06	CONVERT(CHAR(9), CURRENT_TIMESTAMP, 6)
7	Feb 22, 06	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 7)
8	16:26:08	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 8)
9	Feb 22 2006 4:26:08:020PM	CONVERT(CHAR(26), CURRENT_TIMESTAMP, 9)
10	02-22-06	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 10)
11	06/02/22	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 11)
12	060222	CONVERT(CHAR(6), CURRENT_TIMESTAMP, 12)
13	22 Feb 2006 16:26:08:020	CONVERT(CHAR(24), CURRENT_TIMESTAMP, 13)
14	16:26:08:037	CONVERT(CHAR(12), CURRENT_TIMESTAMP, 14)
20	2006-02-22 16:26:08	CONVERT(CHAR(19), CURRENT_TIMESTAMP, 20)
21	2006-02-22 16:26:08.037	CONVERT(CHAR(23), CURRENT_TIMESTAMP, 21)
22	02/22/06 4:26:08 PM	CONVERT(CHAR(20), CURRENT_TIMESTAMP, 22)
23	2006-02-22	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 23)
24	16:26:08	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 24)
25	2006-02-22 16:26:08.037	CONVERT(CHAR(23), CURRENT_TIMESTAMP, 25)
100	Feb 22 2006 4:26PM	CONVERT(CHAR(19), CURRENT_TIMESTAMP, 100)
101	02/22/2006	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 101)
102	2006.02.22	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 102)
103	22/02/2006	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 103)
104	22.02.2006	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 104)
105	22-02-2006	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 105)
106	22 Feb 2006	CONVERT(CHAR(11), CURRENT_TIMESTAMP, 106)
107	Feb 22, 2006	CONVERT(CHAR(12), CURRENT_TIMESTAMP, 107)
108	16:26:08	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 108)
109	Feb 22 2006 4:26:08:067PM	CONVERT(CHAR(26), CURRENT_TIMESTAMP, 109)
110	02-22-2006	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 110)
111	2006/02/22	CONVERT(CHAR(10), CURRENT_TIMESTAMP, 111)
112	20060222	CONVERT(CHAR(8), CURRENT_TIMESTAMP, 112)
113	22 Feb 2006 16:26:08:067	CONVERT(CHAR(24), CURRENT_TIMESTAMP, 113)
114	16:26:08:067	CONVERT(CHAR(12), CURRENT_TIMESTAMP, 114)
120	2006-02-22 16:26:08	CONVERT(CHAR(19), CURRENT_TIMESTAMP, 120)
121	2006-02-22 16:26:08.080	CONVERT(CHAR(23), CURRENT_TIMESTAMP, 121)
126	2006-02-22T16:26:08.080	CONVERT(CHAR(23), CURRENT_TIMESTAMP, 126)
127	2006-02-22T16:26:08.080	CONVERT(CHAR(23), CURRENT_TIMESTAMP, 127)
130	24 ???? 1427 4:26:08:080PM	CONVERT(CHAR(32), CURRENT_TIMESTAMP, 130)
131	24/01/1427 4:26:08:080PM	CONVERT(CHAR(25), CURRENT_TIMESTAMP, 131)

Programmatically add a stylesheet reference

HtmlLink newStyleSheet = new HtmlLink();       
  newStyleSheet.Href = "css/your.css";               
  newStyleSheet.Attributes.Add("type", "text/css");
  newStyleSheet.Attributes.Add("rel", "stylesheet");
  Page.Header.Controls.Add(newStyleSheet); 

Large .suo file causing Visual Studio to hang

Just when I needed it least Visual Studio decided to hang. I restarted it and sat for 10 minutes while it opened my project again. So I restarted the machine, and it did it again.

After a bit of investigation I found that my .suo file was 8.5MB (which is tiny compared to some reports), and renaming this (the safe equivalent of deleting) solved my problems. I lost a few preferences (I haven't fully established what yet, but I run pretty vanilla so there shouldn't be much) but it all works WAY faster than I've become accustomed to.

Perhaps there's a more official way of cleansing the .suo?

Installing ELMAH to log unhandled exceptions in asp.net application

ELMAH logs all your uncaptured errors. It's remarkably easy to implement - I followed the simple instructions on these posts here and here. The latter link has more detail but has a couple of typos in the web.config additions which will become obvious if you use it.

Having functionality like this at your fingertips is very reassuring!

Using one stored procedure in another

Today I had to call a SPROC from another SPROC by sending it a parameter, storing the results in a temporary table, and then looping through the temp table. After some googling and tweaking I came up with this which seems to work a treat. I'm no SQL expert though!

--create temp table
 create table #temp (
    idx int identity(1,1),
    field1 int,
    field2 int)

 -- put data into temp table using other SP
 insert into #temp (field1, field2)
 exec myOtherSproc @paramaterToSend
 
 -- loop through temp table
 declare @counter int

 set @counter = 1

 while @counter < (select max(idx) from #temp)
  begin
   --do whatever you want here
   set @counter = @counter + 1
  end
 
 DROP TABLE #temp