In this tutorial, we’ll show how to create a method, within your ASP.Net code, which returns a Dataset, using C#. To demonstrate this, we’ll be using the Northwind database, which is easily accessible, if you don’t already have it available in your SQL Server. We created a Gridview on our ASP.Net page and used the ‘Rainy Day’ formatting option:

 <asp:GridView ID="GridView1" runat="server" BackColor="White"
BorderColor="#999999" BorderStyle="None" BorderWidth="1px" CellPadding="3"
GridLines="Vertical">
<RowStyle BackColor="#EEEEEE" ForeColor="Black" />
<FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="#DCDCDC" />
</asp:GridView>

Then, in our code, we created the method, which returns a dataset:

private DataSet getData()
        {
// get the connection string
String conn = ConfigurationManager.ConnectionStrings["NW"].ConnectionString;
// build our SQL Select statement (should preferably be a stored procedure)
String mySQL = "Select ProductName, QuantityPerUnit, UnitPrice from Products where CategoryID=1";
DataSet ds;
using (SqlDataAdapter da = new SqlDataAdapter(mySQL, conn))
{
ds = new DataSet();
 da.Fill(ds, "ProductInfo");
}
return ds; // 'returns' the dataset
}

All that is left is to consume, or use the getData() method, to add the data to the Gridview, in some event on the page:
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One of the great things built in to ASP.Net is the ability to compare two strings with one another, Let’s say you’re in the middle of your coding and you need to check two strings against each other and find out if they’re the same or not. With very little code, you can be up and on your way in no time.

While comparing strings, you also have the added possibility to use or not use case sensitivity. Consider the two strings:
my String
my string

There are 3 parameters to this method:
String 1
String 2
Case Sensitivity
Here’s the general, or most common way it’s used:
System.String.Compare(String1, String2, ignoreCase as Boolean (True/False) as Integer
The boolean parameter at the end can be a little tricky to understand, if you’re new to programming. As you can see, the Boolean value is for ‘ignoreCase’. So, considering the two strings above, if you want to compare the strings, and you don’t care to check for case sensitivity, you will use ‘True’. If you do want to compare them, and take case sensitivity into consideration when checking them, you will use ‘False’.

As you can see, it will return an Integer value. if it returns 0, then the strings are equal to one another. If it returns -1, the strings are NOT equal to one another.

So, to use it in programming, you would do something like this:

		Dim String1 as string="my String"
		Dim String2 as string="my string"
		' Ignoring Case:
		if System.String.Compare(String1,String2,True)=0 then
		' put code here if the strings are the same
		else
		' put code here if the strings are NOT the same
		end if

or:
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There are four basic scoping modifiers for methods (subs or functions) that are most used in ASP.Net/VB.Net. The are:

• Private
• Protected
• Friend
• Public

Beginning programmers sometimes have a problem understanding exactly what they are used for. These words are put in front of the Sub or Function. The base functionality is that these modifiers are defining the ‘scope’ in which they are used – in other words, where and how they can be used within the program in which they reside. The following is just a basic run down of what they mean.

Private
Private means that the sub or function is ONLY available/visible to the current class itself.

Protected
Protected means that the sub or function is ONLY available/visible to the current class AND subclasses derived from it.

Friend
Friend means that the sub or function is visible to the current assembly

Public
Public means that the sub or function is visible to all, and can be utilized as such.
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At first glance, the HyperlinkField (used in the GridView) seems fairly straightforward, but on second glance, you might be a little intimidated on how to use it. In this tutorial, we’ll be only focusing on using it in a Gridview which is being populated by a database, so the properties we’ll be looking at will be fewer.

The main concept of the HyperLinkField is to act as a regular HTML hyperlink in your Gridview, using data retrieved dynamically from your datasource.

The four main properties into which we’ll be looking are the DataTextField, HeaderText, DataNavigateURLFields, and DataNavigateUrlFormatString.

We’ll get HeaderText out of the way first since it’s the simplest of all of them. This, of course, is what appears in the Header of the Gridview, atop the HyperlinkField’s column. You can change it any way you’d like and it won’t affect anything else in your data retrieval

Next, we’ll look at the DataTextField. This, too, is fairly straight-forward. It will be what is actually displayed in each row, using the data retrieved from the datasource. For instance, if you’re field/column is from the FirstName field in your database, then, it would display Tom, Cathy, David, etc.

The last two properties at which we’re looking interact with each other. First, think of a link you have to another page. If it were a regular HTML hyperlink, you’d have something like this:
Report
Now, think of this in terms of adding a querystring to the url:
Report

In a Gridview scenario, this column, in each row, could have a different actual querystring based on particular results retrieved from the database in that record. In this scenario, you’d want the actual URL to be the same URL for each record, but the querystring ‘ID’ would be different. For the purpose of this scenario, let’s say the ‘ID’ is coming from a field in the database called ‘MasterID’.

Therefore, to do this, we’d set the DataTextField property to MasterID (which will display the number itself), and we’d set the DataNavigateURLFields property to MasterID (this sets the querystring). Next, in order to get the complete URL (Report.aspx?id=27), we’d also set the DataNavigateURLFormatString to Report.aspx?id={0}. We also need to make sure that the exact path is listed here, so if the Report.aspx file is in a different folder, that needs to be reflected here. Having {0} at the end, tells it to use whatever is listed in the DataNaviageURLFields property for the querystring. That’s basically all there is to it.

So, you’d end up with something like this:
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In most SQLDataSource articles, the data display is usually a Gridview, or a DetailsView. However, in this tutorial, we’re going to look at how to provide Inserting and Updating functions within a page with single-field type controls (TextBox/DropDownList, etc). Sometimes, for simpler pages, these types of controls are a bit overkill, or even with more complex pages where they don’t seem to fit the bill., you might need a more freehand approach

I’m going to use a very simple Insert sample here, with just two textboxes, but you can use any other controls you’d like. In the ASPX page, let’s insert two textboxes and some text, for labeling what should be put in the textboxes, just as you’d see on an average web page, along with a button:

First Name:
<asp:TextBox ID="txtFirstName" runat="server"></asp:TextBox>
Last Name:
<asp:TextBox ID="txtLastName" runat="server"></asp:TextBox>
<br />
<asp:Button ID="btnSubmit" runat="server" Text="Submit" />

Of course, in our imaginary scenario, we’d have a table in the database (let’s call it ‘Test_Table’), with only two columns (Firstname, and Lastname). And along with this, we’d have a stored procedure called ‘Insert_Test’, with two parameters:

CREATE PROCEDURE [dbo].[Insert_Test]
@FirstName varchar(50),
@LastName varchar(50)

AS
Insert into Test_New (FirstName, LastName)
Values (@FirstName, @LastName)

Next, we’ll add a SQLDataSource control, and just call it ‘DS1′:

 <asp:SqlDataSource ID="ds1" runat="server"
ConnectionString="<%$ ConnectionStrings:MyTest_dbConnectionString %>"
InsertCommand="Insert_Test"
InsertCommandType="StoredProcedure"
SelectCommand="Select * from Test">
<InsertParameters>
<asp:Parameter Name="FirstName" Type="String" />
<asp:Parameter Name="LastName" Type="String" />
</InsertParameters>
</asp:SqlDataSource>

For the click event of the ‘Submit’ button, we’ll just put in one line:
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Using the PreviousPage scenario, with Master Pages presents its own particular problems, but they’re not hard to overcome. As you may have noticed, using “PreviousPage” scenario isn’t quite as simple as it looks in all the tutorials. In fact, using most of the tutorials/code samples on the web, doesn’t work at all. That’s specifically because they aren’t taking into consideration, that, with a Master Page, you have a ContentPlaceholder, and you must first look there, to find the data from the previous page.

For those who don’t know, the base samples show a scenario in which the ‘Submit’ button on the first page has it’s PostBackURL property assigned to the second page in the postback scenario. The code, then would look something like:

	Dim Name As TextBox
	Name = Page.PreviousPage.FindControl("txtName")
	Label1.Text = Name.Text

As we stated earlier, if you’re using a Master Page in your website (with a Master Page designated, specifically, in the submitting page), this doesn’t work. In able to do this, you must look in the Content Placeholder of the submitting page, first. Therefore, the code would look more like this:

Dim ph As ContentPlaceHolder = CType(PreviousPage.Master.FindControl("YourContentPlaceholderID"), ContentPlaceHolder
Dim tb As TextBox = CType(ph.FindControl(YourControlID), TextBox)
Label1.Text = tb.Text

In this sample, we first look inside the submitting page, then we find the Contentplaceholder. Then, once we find the contentPlaceholder, we look inside it, to find the control, from which we need to retrieve the data. Here’s a small function which does all this for us, to cut down on repetitive code:
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One of the most common questions on the net about ASP.Net, when coming from a Classic ASP background, is how to handle situations in which conditional programming is necessary. For instance, in Classic ASP, if you had this code:

If recordset("fieldName") <> "" Then
 ' do this
Else
 ' do this
End if

Since, in ASP.Net, we do not have the sequential code, coming throught the page, like it did with Classic ASP, sometimes we’ll have a label or textbox (or whatever), with the same field information which would have been previously contained in‘recordset(“fieldName”)’

.

To handle this, we would create a helper function, in our code section. So, in this case, let’s call the Function ‘CheckItem’. In the tag, we’d start with something like this:

<asp:Label ID="Label1" Text='<%# Container.DataItem("fieldName") %>' Runat="server" />

Next, we’ll add the code for the function:
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