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As far as I know 3-layer architecture is something like this:
Data Access Layer(DAL) <-> Business Layer(BL) <-> User Interface Layer(UI)
Note that tier is diffrent form layer.
DAL is responsible for accessing data from the database (if there is any)
BL is responsible for applying business rules to the data
UI is responsible for displaying the data to the user and providing means for him to change it.
The data travels in special objects called Bussiness Objects.
I strongly recommend that from the DAL to not return data readers, especialy if the DAL component is on a machine and you reader reaches another component on another machine - this thing will not work in a 3-tier architecture.
You could use for the bussiness objects the dataset created by Visual Studio. The newer versions have a functionality which separate the business objects (data tables and data rows) from the table adapters in different namespaces (even different projects I think).
Also I think there isn't a "good tutorial", but different opinions, read a couple of them and then form your own. 
I have no smart signature yet...
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Thanks 4 the answer, could you give me the example?
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As I said, there are lots of examples on the net, just google for them.
I have no smart signature yet...
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I suggest you google for nHibernate or Linq to Entities.
These both map business objects to your relational database(ORM) with varying degrees of success, forming a DAL for you.
I have seen various DALs written with data sets, and would *strongly* advise against it, they work initially for small object sets, but becomes a nightmare as soon as the comlexity increases a little.
Dalek Dave: There are many words that some find offensive, Homosexuality, Alcoholism, Religion, Visual Basic, Manchester United, Butter.
Pete o'Hanlon: If it wasn't insulting tools, I'd say you were dumber than a bag of spanners.
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I have heard about nHibernate but it is in java, there is in .net too?
and LINQ to Entities, this new to me, I've learn it but still not familiar with the code.I need more practice, maybe after this project done thanks
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Hybernate is the java version. nhybernate is the .NET implementation.
"WPF has many lovers. It's a veritable porn star!" - Josh Smith As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
My blog | My articles | MoXAML PowerToys | Onyx
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hi friends...this is my code
please tell me + -
DAL
public static OleDbDataReader GetAll(OleDbConnection conn, bool status)
{
try
{
string query =
"SELECT [Id], [Name], [CreatedDate], [CreatedBy], " +
" [UpdatedDate], [UpdatedBy] " +
"FROM [Role] " +
"WHERE [Status] = @pStatus " +
"ORDER BY [Name] ASC";
OleDbCommand cmd = new OleDbCommand(query, conn);
OleDbParameter pStatus = cmd.Parameters.Add("@pStatus",
OleDbType.Boolean);
pStatus.Value = status;
OleDbDataReader dr = cmd.ExecuteReader();
return dr;
}
catch (OleDbException ex)
{
throw new Exception("OleDb Error: " + ex.Message);
}
catch (Exception ex)
{
throw ex;
}
}
BLL
public List<Role> GetAll(bool status)
{
List<Role> listRole = new List<Role>();
try
{
if (conn.State != ConnectionState.Open)
{
conn.Open();
}
OleDbDataReader dr = RoleData.GetAll(conn, status);
if (dr.HasRows)
{
while (dr.Read())
{
Role role = new Role();
role.Id = int.Parse(dr["Id"].ToString());
role.Name = dr["Name"].ToString();
role.CreatedBy = dr["CreatedBy"].ToString();
role.CreatedDate = (string.Empty.Equals(dr["CreatedDate"].ToString()) ?
DateTime.MinValue :
DateTime.Parse(dr["CreatedDate"].ToString()));
role.UpdatedBy = dr["UpdatedBy"].ToString();
role.UpdatedDate = (string.Empty.Equals(dr["UpdatedDate"].ToString()) ?
DateTime.MinValue :
DateTime.Parse(dr["UpdatedDate"].ToString()));
listRole.Add(role);
}
}
return listRole;
}
catch (OleDbException ex)
{
throw new Exception("OleDb Error: " + "\n" + ex.Message);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
conn.Close();
}
}
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Can anyone help me in detecting vehicles form still images or from video.
what I want to do is, detect the vehicles and get the vehicle count.
This system is developed for my college project.
I'm really appreciated if someone can give me any sample code or any similar source code for reference.
Thank you..
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Repost
modified on Saturday, May 8, 2010 3:23 AM
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I don't think it is possible to detect vehicle from image/video.
Because for detecting it we need to implement algorithm for
detection.
I do not found such algorithm anywhere. (However face recognition algorithm exists to do the same.)
Jinal Desai - LIVE
Experience is mother of sage....
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Cool answer, if others can't do it, then I surely can't! 
I have no smart signature yet...
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The worst bit is that judging by the quality of his other answers, he is serious...
I have learnt that you can not make someone love you, all you can do is stalk them and hope they panic and give in.
Apathy Error: Don't bother striking any key.
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It is possible to do. Law Enforcement uses software like that for license plate recognition. They could be driving down the road and run every license plate they pass instantly. Pretty impressive software but doubt it is open to C#.
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Jinal Desai - LIVE wrote: I don't think it is possible to detect vehicle from image/video.
This may sound like a stupid question, but how do you think these things work:
1) Digital Speed Cameras.
2) Automatic number plate readers
3) Congestion charge cameras
4) etc., etc., etc.
So yes, it is possible. The algorithms are quite complex, and generally you may find that they are proprietary, and thus not normally posted on the net for everyone to read.
Just because your casual search cannot find something does not make it impossible.
I have learnt that you can not make someone love you, all you can do is stalk them and hope they panic and give in.
Apathy Error: Don't bother striking any key.
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If I think from your perspective then
detection of any object (complex/structural) is
possible by latest technologies.
However, they are not for public use (may be because of
they are in experimental stage or not perfect at all)...
I just answering from possibility perspective. However
perspective and thought processes are different from
man to man.
But in current scenario for "ruknil" it is equivalent to
impossible ( I M Possible).
Hope you understand!
Jinal Desai - LIVE
Experience is mother of sage....
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ohh really?? 
so Jinal Desai, can't I use any image processing techniques for this?
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Obviously you can...
But I am not sure whether it gives
you exact detection or not....
(nearly imperfect)
Jinal Desai - LIVE
Experience is mother of sage....
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thanks for the helping dude..and if you fine any similar code just let me..it's great help to me..thank you again.. 
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Jinal Desai - LIVE wrote: I don't think it is possible to detect vehicle from image/video.
Jinal Desai - LIVE wrote: Obviously you can.
Make your mind up?
I have learnt that you can not make someone love you, all you can do is stalk them and hope they panic and give in.
Apathy Error: Don't bother striking any key.
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Jinal Desai - LIVE wrote: But in current scenario for "ruknil" it is equivalent to
impossible ( I M Possible).
How do you suddenly know about the situation ruknil is in?
This was his first question, and his bio data is sparse - either you know him personally, or you are guessing that he is a complete beginner, and has insufficient experience.
If you mean "I don't think you can do it because I can't" then say that. But do not assume the experience or ability level of any poster based on his first question.
Just replying "it's not possible" as you did when it patently is possible (although complex) gives the wrong impression about this site, and a certain impression about you.
I have learnt that you can not make someone love you, all you can do is stalk them and hope they panic and give in.
Apathy Error: Don't bother striking any key.
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I'll give you the answer I gave somebody else when they asked about automatic numperplate recognition (ANPR):
"Unfortunately, you aren't going to be given the code to do this as this is a hugely complicated area, with commercial systems going for huge amounts of money. Typically ANPR systems make use of several stages to identify the number plate, these stages being:
1. Plate location. This step is responsible for identifying where the plate is in a picture.
2. Plate translation. Orienting and sizing the image, compensating for skew.
3. Image normalisation. Adjusting the brightness/contrast of the image.
4. Segmentation. Finding the characters themselves (i.e. removing items such as flags).
5. Optical Character Recognition.
Now, ANPR requires cameras to take pictures at very high speeds, and requires the processing to take place very quickly, which means that .NET is probably not going to be the most appropriate choice for processing the image (which typically requires sub-second processing). Typically these systems are written in C++ or C, are highly optimised and make use of image processing techniques such as edge detection and sharpening filters."
Now, just because you aren't going to be given the code doesn't mean that it's experimental. Police forces around the world are using this successfully right now - and courts accept this as evidence; something that wouldn't happen if they judged it experimental. More importantly, you can't judge successfully whether or not it's beyond the OPs experience - he may be a genius just looking for a little nudge.
"WPF has many lovers. It's a veritable porn star!" - Josh Smith As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
My blog | My articles | MoXAML PowerToys | Onyx
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Ummmm[^][^]
.45 ACP - because shooting twice is just silly
-----
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"The staggering layers of obscenity in your statement make it a work of art on so many levels." - J. Jystad, 2001
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Hi all,
I have a question as to where to begin with what I'd like to to in a datagridview. The datagridview is bound to a dataset data table. One of the columns is a combobox. I want another column that is also a combobox too, but filtered based upon the selection of the first combobox.
Ex.
Column 1
Force
Column 2
lb
N
ton
or
Column 1
Torque
Column 2
in-lb
N-m
etc, etc.
My initial thought is to have an if loop that build the collection in the second combobox based upon the selection of the first. However, I don't know where this would go (even if that were to be the most efficient way to do it). Any help would be greatly appreciated.
Thanks.
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You might want to start from here.
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You should try ItemDatabound event to populate the second DropDownList
protected void dgEmpleados_ItemDataBound(object sender, DataGridItemEventArgs e)
{
DataTable dt = (DataTable)((DataGrid)sender).DataSource;
if (dt.Rows.Count > 0 && e.Item.ItemIndex > -1)
{
((CheckBox)e.Item.Cells[0].FindControl("chkSeleccionar")).Checked =
Convert.ToBoolean( dt.Rows[e.Item.ItemIndex][_COL_SELECCIONAR].ToString());
((TextBox)e.Item.Cells[0].FindControl("txtGridObservaciones")).Text =
dt.Rows[e.Item.ItemIndex][_COL_OBSERVACIONES].ToString();
}
}
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