20 replies to this topic

[percis]

I want to create a form. For example, i have a rectangle with length 3m and breadth 2m. To find the area of the rectangle is length * breadth.
To solve this pblm, how to do I use database in microsoft visual studio 2010; what are the codings?

[Tonchi]

http://msdn.microsof...y/ms233763.aspx
this is how you can create a db in vs
for how to communicate with database inside C# you must look inside topic that i created here...it's
Null Values In Table After Saving Data

[kernelcoder]

percis, you want to find the area of a rectangle which width/height are given. Why do you need a database to do that?

[percis]

percis, you want to find the area of a rectangle which width/height are given. Why do you need a database to do that?

i get the values such as length and breadth from the database.

[Orjan]

something similar to

SELECT width, height, (width * height) AS area FROM...

[kernelcoder]

OK ... Let us assume that you have a database named 'Geometry' in SQL server which has a table named 'Rectangles' -- the table has two columns, width & height, of type int. Now our job is to retrieve that table data and show in a data-grid but with an extra column that will show the 'area' of the rectangle. So the steps are...

• Create a SqlConnection object with the connection string for that database and open the connection.
• Create a SqlAdapter object for that connection object and with the SQL query Orjan posted.
• Create a DataTable object and ask the adapter to fill for that SQL query.
• Add an extra column in the DataTable object -- 'Area'.
• In a foreach loop, for each row, calculate the area from the width & height and update the each row of the DataTable object
• Finally assign the DataTable object as a DataSource to the DataGridView.

And here is the code for the steps...

void DBTest()
{
   try
   {
      // Step 1
      System.Data.SqlClient.SqlConnection conn =
      new System.Data.SqlClient.SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=Geometry;Integrated Security=True");
      conn.Open(); 

      // Step 2
      System.Data.SqlClient.SqlDataAdapter adapter =
new System.Data.SqlClient.SqlDataAdapter("SELECT * FROM Rectangles", conn);

      // Step 3
      System.Data.DataTable table = new System.Data.DataTable();
      adapter.Fill(table);

      // Step 4
      table.Columns.Add("Area");

      // Step 5
      foreach (System.Data.DataRow row in table.Rows)
      {
            object[] cells = row.ItemArray;
            cells[2] = Convert.ToInt32(cells[0]) * Convert.ToInt32(cells[1]);
            row.ItemArray = cells;
      }

      // Step 6
      dataGridView1.DataSource = table;
   }
   catch (Exception exc)
   {
      Console.WriteLine("Error: " + exc.Message);
   }
}

[Orjan]

my query does the calculation and adds the field area, kernelcoder, so that part shouldn't be needed in your code.

[kernelcoder]

my query does the calculation and adds the field area, kernelcoder, so that part shouldn't be needed in your code.

Agreed. So foreach loop can be removed.

[percis]

OK ... Let us assume that you have a database named 'Geometry' in SQL server which has a table named 'Rectangles' -- the table has two columns, width & height, of type int. Now our job is to retrieve that table data and show in a data-grid but with an extra column that will show the 'area' of the rectangle. So the steps are...

• Create a SqlConnection object with the connection string for that database and open the connection.
• Create a SqlAdapter object for that connection object and with the SQL query Orjan posted.
• Create a DataTable object and ask the adapter to fill for that SQL query.
• Add an extra column in the DataTable object -- 'Area'.
• In a foreach loop, for each row, calculate the area from the width & height and update the each row of the DataTable object
• Finally assign the DataTable object as a DataSource to the DataGridView.

And here is the code for the steps...

void DBTest()
{
   try
   {
	  // Step 1
	  System.Data.SqlClient.SqlConnection conn =
	  new System.Data.SqlClient.SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=Geometry;Integrated Security=True");
	  conn.Open();

	  // Step 2
	  System.Data.SqlClient.SqlDataAdapter adapter =
new System.Data.SqlClient.SqlDataAdapter("SELECT * FROM Rectangles", conn);

	  // Step 3
	  System.Data.DataTable table = new System.Data.DataTable();
	  adapter.Fill(table);

	  // Step 4
	  table.Columns.Add("Area");

	  // Step 5
	  foreach (System.Data.DataRow row in table.Rows)
	  {
			object[] cells = row.ItemArray;
			cells[2] = Convert.ToInt32(cells[0]) * Convert.ToInt32(cells[1]);
			row.ItemArray = cells;
	  }

	  // Step 6
	  dataGridView1.DataSource = table;
   }
   catch (Exception exc)
   {
	  Console.WriteLine("Error: " + exc.Message);
   }
}

thaks a lot for the solution. I'm lost along the way. Is it possible to from step1 as where should i click in print screen and where should i enter the coding? Please....Im anxiously waiting for ur reply.

[kernelcoder]

If you just want to execute the code successfully, you can call the DBTest method from your form's Load event handler. But note that you have a have a sql database and you have to change the connection string accordingly.

[percis]

If you just want to execute the code successfully, you can call the DBTest method from your form's Load event handler. But note that you have a have a sql database and you have to change the connection string accordingly.

I'm lost. i really need help in setting up sql database/ any step from the beginning. Im using microsoft visual 2010. could u help me?

[kernelcoder]

First you need to install, Microsoft SQL Server. Is it there installed on your machine? Note that, you also need to install SQL Management Studio. If yes, the rest is easy to create a database and table -- read this tutorial about it.

However, we can use Microsoft Access Database to store the height and width for rectangles. If you want to use MS-Access, we need to change the code a bit. Let us know which one you have successfully installed on your machine.