ASP.NET

Re: common practice for development 3 tiered application

15-Nov-09 17:45

could you please provide me small correct snippet as to how it should look. I created one but not sure if its correct.

Public class Product
{
  private string _productId;
  ...
  private Category _category;

 public Product()
{
  this.ProductId = "";
  this.Category.CategoryId = 0;
}

public Product(....parameter for product, string categoryId)
{
...
 this.category.CategoryId = categoryId;
}
public Category category
        {
            get { return _category; }
            set { _category = value; }           
        }
public ProductId
        {
            get { return _productId; }
            set { _productId= value; }           
        }

modified on Monday, November 16, 2009 12:04 AM

Christian Graus15-Nov-09 19:37

Re: common practice for development 3 tiered application

15-Nov-09 19:37

Seems OK to me.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

uglyeyes15-Nov-09 22:03

Re: common practice for development 3 tiered application

15-Nov-09 22:03

I thought so too. but do I need to pass this instance into class constructor?

public Product()
{
this.Category = null;
}
public Product(parameters..., Category c)
{
...
this.Category = c
}
...
...
 public Category cat
        {
            get { return _category; }
            set { _category = value; }           
        }

part of my BLL
   public static class myBLL
    {
        public static List&lt;Product&gt; GetProducts(string CountryName, string AdCity, string AdSubCatType)
        {
            return myDAL.Instance.GetProducts(CountryName,AdCity,AdSubCatType);
        }
part of my DAL

public List&lt;Product&gt; GetProductss(string CountryName, string AdCity, string AdSubCatType)
        {
            using (SqlConnection oConn = new SqlConnection(_connectionString)) {
                string strSql = "spGetProductListList";
                SqlCommand oCmd = new SqlCommand(strSql, oConn);
                oCmd.CommandType = CommandType.StoredProcedure;
                oCmd.Parameters.Add(new SqlParameter("@CountryName", SqlDbType.NVarChar, 50)).Value = CountryName;
                oCmd.Parameters.Add(new SqlParameter("@AdCity", SqlDbType.NVarChar, 200)).Value = AdCity;
                oCmd.Parameters.Add(new SqlParameter("@AdSubCatType", SqlDbType.NVarChar, 50)).Value = AdSubCatType;               
               
                oConn.Open();
                string m = oCmd.ToString();
                
                // execute query
                SqlDataReader oReader = oCmd.ExecuteReader();
                List&lt;Product&gt; products= null;
                products = GetProductCollectionFromReader(oReader);
                oReader.Close();
                return products;
            }
        }
protected List&lt;Product&gt; GetProductCollectionFromReader(IDataReader oReader)
        {
            List&lt;Product&gt; products = new List&lt;Product&gt;();
            while( oReader.Read() )
                // read line by line and map to an object
                products.Add(GetProductFromReader(oReader));

            return products;
        }
protected Product GetProductFromReader(IDataRecord oReader)
        {
            Product product = new Product();
            product.ProductId = (int)oReader["ProductId"];
            ....
            product.Category.CategoryName  = (string)oReader["CategoryName"];//I get exception here not sure how can i set value of category
            product.Category.CategoryCode = (string)oReader["CategoryCode"];

          
            return product;
        }

uglyeyes15-Nov-09 22:16

I want to create paging by Datalist language VB.net [modified]

15-Nov-09 22:16

I get null reference exception.

sunshinesnow15-Nov-09 16:13

sunshinesnow

15-Nov-09 16:13

Please describe how to do paging of the information of each page which includes 5 topics. Accordingly, there is coding of .vb for reference.

modified on Sunday, November 15, 2009 10:21 PM

Re: I want to create paging by Datalist language VB.net

Not Active15-Nov-09 16:18

15-Nov-09 16:18

A simple search of google will provide you the answer.

Also, please format your code with pre tags as described here[^] Most people will ignore posts that are not properly formatted.

I know the language. I've read a book. - _Madmatt

Sintax problem

Maxdd 715-Nov-09 15:46

15-Nov-09 15:46

Let's say I have in index.aspx.cs Page_load():

int id=1;

And I have a gridview populated by MS SQL, and I have the following selectcommand:

SelectCommand="SELECT * FROM [Filmes] WHERE [ID_Users]=' id '"

I need to use that variable that way.

Is it possible? What is the correct syntax? I tried many ways but cant do it. Really appreciate your help.

_Damian S_15-Nov-09 15:55

_Damian S_

15-Nov-09 15:55

The syntax you are after is this:

SelectCommand="SELECT * FROM [Filmes] WHERE [ID_Users]= " & id

However, I would strongly recommend you use a stored procedure rather than SQL embedded in your code.

I don't have ADHD, I have ADOS... Attention Deficit oooh SHINY!!

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Maxdd 715-Nov-09 16:01

15-Nov-09 16:01

One step at the time Smile | :)

Not Active15-Nov-09 16:20

15-Nov-09 16:20

You have been given this advise before. Time to take heed. If you want to learn how to code, learn it right.

I know the language. I've read a book. - _Madmatt

Christian Graus15-Nov-09 17:26

15-Nov-09 17:26

Maxdd 7 wrote:
One step at the time

You say that and yet you post asking about every topic under the sun, without ever taking the time to properly learn anyting, or consider any of the good advice you are given

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Maxdd 715-Nov-09 17:31

15-Nov-09 17:31

Well,

Those are two different questions.

Maybe I should read some things first, that is one mistake and I assume.

Regarding the good advice I received, I consider them. I just no apply them for now, because I believe I should not try drive a truck, when I dont know how to drive a car.

Not Active15-Nov-09 18:10

15-Nov-09 18:10

That's the point you are missing, you are trying to taught how to ride a bike before you get near the car.

I know the language. I've read a book. - _Madmatt

Maxdd 715-Nov-09 18:23

15-Nov-09 18:23

I know you are right I'm just trying to make you understand my point of view.

Until some days ago, I never coded a line of C# and used ASP.NET controls. I dont have a book (or e-book) or anyone I know who could teach me. The few I learn, was throught google, and even by google it could be difficult find the information I need. There are so many things of ASP.NET (I never imagined!), and then exists .NET 1.1, 2.0, 3.0 (...) VB.NET, older versions, near versions (...) Sometimes it could be difficult start coding in this conditions, because I dont know where to stand, where to look.

But ok, from now on, I will try to follow your advices, and just post questions (if necessary) about it.

My apologies for any incovenience.

Christian Graus15-Nov-09 19:41

15-Nov-09 19:41

Maxdd 7 wrote:
Until some days ago, I never coded a line of C# and used ASP.NET controls.

Which means you're an idiot for trying ASP.NET at all. You need good C# first.

Maxdd 7 wrote:
I dont have a book

If you can't buy one, then at least recognise what the right sequence is. I taught myself and I started with C++, then learned MFC. No-one told me that, it was common sense.

Maxdd 7 wrote:
. The few I learn, was throught google, and even by google it could be difficult find the information I need.

99% of the questions asked here, it's trivial to get answers with google. The problem is you're trying to ask complex questions, before knowing the answers to the easy ones.

Maxdd 7 wrote:
There are so many things of ASP.NET (I never imagined!), and then exists .NET 1.1, 2.0, 3.0 (...) VB.NET, older versions, near versions (...) Sometimes it could be difficult start coding in this conditions, because I dont know where to stand, where to look.

C#. Ignore VB.NET. Learn basic C#, preferably writing console apps. Then you could progress to web pages, perhaps. Don't even try to learn SQL before you know C# really well. Don't even think of ASP.NET before you learn the language that drives it.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Christian Graus15-Nov-09 19:38

binding an arraylist to datalist and implement pagination in Presentation Layer [modified]

15-Nov-09 19:38

Maxdd 7 wrote:
I just no apply them for now, because I believe I should not try drive a truck, when I dont know how to drive a car.

Your problem is that you choose to drive the truck instead of starting with the damn car.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

uglyeyes15-Nov-09 12:16

Re: binding an arraylist to datalist and implement pagination in Presentation Layer

15-Nov-09 12:16

Hi!

I am trying to seperate my PL, BLL and DAL. I have managed successfully bind data to datalist via arraylist. Earlier, I was just doing direct calls to database for pagination using dataset and dataadapter. Since I am binding datalist via arraylist pagination seems bit complicated. below is my code. could someone please help?

 public void ProductList()
            {

                  List&lt;product&gt; products = new List&lt;product&gt;();

                  //DataSet dsProduct = new DataSet();
                  //sqlConn = new SqlConnection(ConfigurationManager.ConnectionStrings["conString"].ConnectionString);
                  //string strSql = string.Format(strSelectSQL, Session["CountryName"], Session["City"], Session["AdType"]);
                  //sqlDataAdapt = new SqlDataAdapter(strSql, sqlConn);
                  if (!Page.IsPostBack)
                  {
                        products = myBLL.Getproducts(Session["CountryName"], Session["City"], Session["AdType"]);
                        //sqlDataAdapt.Fill(dsProduct);
                        //dsproduct = myBLL.Getproducts(Session["CountryName"], Session["City"], Session["AdType"]);
                        lblRecordCount.Text = products.Count.ToString();
                        products = null;
                        List&lt;product&gt; products = new List&lt;product&gt;();
                  }
                  sqlDataAdapt.Fill(dsProduct, Convert.ToInt32(lblCurrentIndex.Text), Convert.ToInt32(lblPageSize.Text), "product");
                  dlproductList.DataSource = dsproduct.Tables["product"].DefaultView;
                  dlproductList.DataBind();
                  sqlConn.Close();
                  ShowCounts();
            }


//DataList Pagination Scripts

            public void ShowFirstPage(System.Object s, System.EventArgs e)
            {
                  lblCurrentIndex.Text = "0";
                  productList();
            }

            public void ShowPreviousPage(System.Object s, System.EventArgs e)
            {

                  lblCurrentIndex.Text = Convert.ToString(Convert.ToInt32(lblCurrentIndex.Text) - Convert.ToInt32(lblPageSize.Text));
                  if (Convert.ToInt32(lblCurrentIndex.Text) &lt; 0)
                  {
                        lblCurrentIndex.Text = "0";
                  }
                  productList();
            }

            public void ShowNextPage(System.Object s, System.EventArgs e)
            {
                  if ((int)Convert.ToInt32(lblCurrentIndex.Text) + Convert.ToInt32(lblPageSize.Text) &lt; Convert.ToInt32(lblRecordCount.Text))
                  {
                        lblCurrentIndex.Text = Convert.ToString(Convert.ToInt32(lblCurrentIndex.Text) + Convert.ToInt32(lblPageSize.Text));
                  }
                  productList();
            }

            public void ShowLastPage(System.Object s, System.EventArgs e)
            {
                  int intMod = 0;
                  intMod = Convert.ToInt32(lblRecordCount.Text) % Convert.ToInt32(lblPageSize.Text);
                  if (intMod &gt; 0)
                  {
                        lblCurrentIndex.Text = Convert.ToString(Convert.ToInt32(lblRecordCount.Text) - intMod);
                  }
                  else
                  {
                        lblCurrentIndex.Text = Convert.ToString(Convert.ToInt32(lblRecordCount.Text) - Convert.ToInt32(lblPageSize.Text));
                  }
                  productList();
            }

            private void ShowCounts()
            {
                  lblCounts.Text = "|Total Rows: &lt;b&gt;" + lblRecordCount.Text;
                  lblCounts.Text += "&lt;/b&gt; | Page:&lt;b&gt; ";
                  lblCounts.Text += Convert.ToString(Convert.ToInt32(Convert.ToInt32(lblCurrentIndex.Text) / Convert.ToInt32(lblPageSize.Text)) + 1);
                  lblCounts.Text += "&lt;/b&gt; of &lt;b&gt;";
                  if ((Convert.ToInt32(lblRecordCount.Text) % Convert.ToInt32(lblPageSize.Text)) &gt; 0)
                  {
                        lblCounts.Text += Convert.ToString((Convert.ToInt32(lblRecordCount.Text) / Convert.ToInt32(lblPageSize.Text) + 1));
                  }
                  else
                  {
                        lblCounts.Text += Convert.ToString(Convert.ToInt32(lblRecordCount.Text) / Convert.ToInt32(lblPageSize.Text));
                  }
                  lblCounts.Text += "&lt;/b&gt; |";
            }

modified on Monday, November 16, 2009 12:05 AM

Abhishek Sur15-Nov-09 12:29

Re: binding an arraylist to datalist and implement pagination in Presentation Layer

15-Nov-09 12:29

Dont you think using PagedDataSource can make life easier for you in this regard (Of course if you want to do this manually not using DataPager)

Sniff | :^)

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
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uglyeyes15-Nov-09 13:15

Re: binding an arraylist to datalist and implement pagination in Presentation Layer

15-Nov-09 13:15

Hi! but i would like to show something like

Total count: X and Page 1 of 7

how do I get above done using pagedatasource class as i have only seen previous next button only

thank you for your help!

Abhishek Sur15-Nov-09 21:15

Re: binding an arraylist to datalist and implement pagination in Presentation Layer

15-Nov-09 21:15

Yes you will get the CurrentPageIndex, CountofPages, Nos of items in a single page etc from the object.

Use
PageSize = No of rows each page will contain (You need to set this)
PageCount = No of Pages.
CurrentPageIndex = Page that is called for.

etc.

uglyeyes wrote:
Total count: X and Page 1 of 7

Hey, if this is what you require, why do you need to build a custom html using PageDataSource, rather use DataPager control. It is easier to build these using <asp:DataPager

Check this :
http://msdn.microsoft.com/en-us/library/cc295263(Expression.30).aspx[^]

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
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Not Active15-Nov-09 12:32

15-Nov-09 12:32

Please use the pre tags when posting code.

Most people here will ignore the post if it isn't properly formatted.

I know the language. I've read a book. - _Madmatt

Maxdd 715-Nov-09 11:09

Re: Login problem with ExecuteScalar();

15-Nov-09 11:09

My users table is that:

CREATE TABLE Users(
ID_Users INT IDENTITY(1,1),
Username VARCHAR(30) UNIQUE,
Password VARCHAR(100) DEFAULT 'password',
Nivel tinyint DEFAULT '3',
PRIMARY KEY(ID_Users));

When users give username and password executes the following code:

string sqlUserName;
       sqlUserName = "SELECT ID_Users, Username,Password,Nivel FROM Users ";
       sqlUserName += " WHERE (Username ='" + UserName + "')";
       sqlUserName += " AND (Password ='" + Password + "')";
       SqlCommand com = new SqlCommand(sqlUserName, Conn);

string existe;
       existe = (string)com.ExecuteScalar();

if (existe != null)
(...)

The problem is, I added five minutes ago "SELECT ID_Users". Now I have the error: "unable to cast int32 to string".

I dont understand, because I use sucessfuly tinyint and there is no problem. Ok, its not a int32, but in the end its not the same thing? What should I do ?

EDIT: looks like if I do:

object existe;
existe = com.ExecuteScalar();

There's no error. Can I use it with no problem's ?

Abhishek Sur15-Nov-09 11:31

Re: Login problem with ExecuteScalar();

15-Nov-09 11:31

To make you understand, I guess ExecuteScalar executes a query and returns only the first column of the first row. All others are just ignored. So why do you select them ??

Anyways, ExecuteScalar returns an object. So you might use

string existe = com.ExecuteScalar().ToString();

But let me remind you, if there is no row selected, this line will through an error. So rather check the object first.

object result = com.ExecuteScalar();
if(result != null)
 string existe = result.ToString();

Hope this is fine. Or you can also check Count(*) to determine if anyone is selected or not in the query.

Thumbs Up | :thumbsup:

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
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Not Active15-Nov-09 12:01

Re: Login problem with ExecuteScalar();

15-Nov-09 12:01

Why are you trying to use a string as a boolean?

The more acceptable way to handle this would...

SELECT CASE COUNT(*) WHEN 0 THEN 0 ELSE 1 END 
FROM Users WHERE Username...

return Convert.ToBoolean(cmd.ExecuteScalar());

I know the language. I've read a book. - _Madmatt

Abhishek Sur15-Nov-09 12:05