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What is the difference in using the column index and the column name?
which one is advantageous?
-- modified at 2:11 Monday 14th May, 2007
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Both have their own importance.
Lets consider an example
Suppose you are getting data from Database using a Stored procedure.
Stored procedure contains Select as..
Select ID, Name, Value from Table1
When you will use this DB procedure in the C#..
You have 2 options Either to get by Column name or by Index..
<br />
long id;<br />
String Name, Value;<br />
<br />
id = (long) lv_DtSet.Tables[0].Rows[0][0];<br />
Name = (String) lv_DtSet.Tables[0].Rows[0][1];<br />
Value = (String) lv_DtSet.Tables[0].Rows[0][2];<br />
<br />
id = (long) lv_DtSet.Tables[0].Rows[0]["ID"];<br />
Name = (String) lv_DtSet.Tables[0].Rows[0]["Name"];<br />
Value = (String) lv_DtSet.Tables[0].Rows[0]["Value"];<br />
Now, if you look at Index case you don't know which value u r retrieving.
So, if someday DB person changes sequence of columns say..
Select ID, Value, Name from Table1
you r in trouble. B'coz no exception will be raised.. bt Name and Value will get interchanged.
So I will prefer to use Column name in this case. B'coz Changing of column name in DB is less likely. And eventhough the Sequence of columns in Select query gets changed, u don't have to change your code.
But there are some times.. u don't know column names OR u want to read data serially Column1, column2 etc.. then use Column indexes.
Depends on situation.
But I will prefer to use Column name as far as possible.
And by the way its.. ROHAN
"If our Mind can, the Program can !!" ≡ ░Ŗổђầŋ٭ ≡
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Is there any difference in the speed that who will get u the records quickly???????
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As long as i know there is no difference in speed while retrieving data.
"If our Mind can, the Program can !!" ≡ ░Ŗổђầŋ٭ ≡
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This[^] will convert it for u.
"If our Mind can, the Program can !!" ≡ ░Ŗổђầŋ٭ ≡
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Hi all,
I was wondering if anyone knew of a relatively easy way to draw a random line through a value of X on a graph.
I then need to pull two points from the line.
None of this needs to be graphical or even displayed i just need the points as text output to be use later.
Any ideas at all would be greatly appreciated.
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Use random numbers
Dim rnd As Random
s = rnd.Next()
Gg
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thats not exactly what I meant
I'm not looking for truly random numbers
I'm looking for 2+ random points on a line that intersects x at a given point
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If you generate the equation of the line, you can sub x values back in and calcualte y values.
e.g.
y = x + 2<br />
Say x = 2<br />
y = (2) + 2<br />
y = 4<br />
Therefore the point = (2,2)
Looks easy on paper, yet i imagine it's somewhat more difficult to accomplish in code. Hope this gets you started.
Posted by The ANZAC
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hi,
i have application in which No MDI form present.My problem is that i found one icon for each open form when i press ALT + Tab keys. However all form (Except main form) ShowInTaskBar property is set to false.
i want to show only single icon for my application (whether one or multiple form is open)when user press ALT + TAB keys to switch between multiple application.
Rupesh Kumar Swami
Software Engineer,
Integrated Solution,
Bikaner (India)
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If u r asking for same icon for all the forms in ur application.
then u need to choose a common icon for all forms.
Is this what u r asking for???????
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hi Nilish ,
i m not asking same icon for all the forms.
My Problem is that when I press ALT+TAB key then there r more than one icon in SWITCH WINDOW for my application. No. of icons in SWITCH WINDOW is equal to opened form in my applicaton. How can i prevent this thing .
Rupesh Kumar Swami
Software Engineer,
Integrated Solution,
Bikaner (India)
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Rupesh , I think u need to take the MDI .Then u don't even need to set the ShowInTaskbar property to true.
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hi nilish,
my main form contains some container control .so i can not change the main form to MDI.
Rupesh Kumar Swami
Software Engineer,
Integrated Solution,
Bikaner (India)
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Sory Boss, I can't help u in getting rid of icon to appear in the switch window.
For that u need to wait for people like christian Graus , Kubben etc...... to join this thread
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hi Rupesh,
which method do you use for opening forms!?
you should use showdialog() instead of show() method
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hi dear,
Thank you very much.
Rupesh Kumar Swami
Software Engineer,
Integrated Solution,
Bikaner (India)
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Is there a way in VB.NET 2005 to close all forms (or hide) except the one that is being loaded, without typing a load of code to hide each form?
Cheers
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I don't remember off the top of my head, but I think you can loop through all of the Form objects and hide all but the one you want to keep open. Hope this starts you off on the right foot...
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The Application object has a property that lists all open forms, you can iterate over that.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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What do you mean, application.exit.... something??? Im not a wiz at vb by the way, just a beginner!
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harveyhanson wrote: Im not a wiz at vb by the way, just a beginner!
This makes me question what you're really trying to do with this.
The Application object has a collection called OpenForms . All you need to do is iterate over this collection and call Hide on each form, taking care not to hide the form you want to show.
For Each f As Form in Application.OpenForms
' Make sure we're not hiding the form this code is on...
If f Is Not Me Then
f.Hide
Next
Next
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The aim is to make a goodbye screen, but at the mo it is just over the top of the current form, whereas i want that to be the only form shown!
I will have a go with this statement
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