I'm running some experiments to grasp the concept behind managing databases in C# an Visual Studio. What I did was creating a simple sdf database with just one table "Books", consisting of two collumns - auto-incrementing key "ID" and "Author" field. I tried to create a DataSet object to load, modify and store changes. The program writes two numbers to console - the count of rows in the DataSet right after loading data from database, and one after modifying it but before updating it to the sdf.
What happens, and has me at a total loss, is this:
First run, I get exactly what I expected to see, that is 0 1 - empty table was successfully loaded, and an item was added to the dataset.
When I run the code again I get 1 2. Then 2 3, 3 4 and so forth, as expected. Untill I refresh the database and try to see it's contents via Server Explorer - all that I see is empty table. Also when I run the program once again afterwards, I get 0 1 response like in the beginning.
Here's the code I'm using:
namespace DatasetTesting{
class Program
{
static void Main(string[] args)
{
string conString = "Data Source=Books.sdf;Persist Security Info=False;Password=pass";
SqlCeConnection objConn = new SqlCeConnection(conString);
objConn.Open();
SqlCeDataAdapter da = new SqlCeDataAdapter("Select * from Books", objConn);
BooksDataSet booksSet = new BooksDataSet();
da.FillSchema(booksSet,SchemaType.Source, "Books");
da.Fill(booksSet, "Books");
Console.Out.WriteLine(booksSet.Books.Rows.Count);
BooksDataSet.BooksRow book = booksSet.Books.NewBooksRow();
book.Author = "Tolkien";
booksSet.Books.AddBooksRow(book);
Console.Out.WriteLine(booksSet.Books.Rows.Count);
SqlCeCommandBuilder comBuilder = new SqlCeCommandBuilder(da);
da.Update(booksSet, "Books");
Console.In.ReadLine();
}
}
I must admit that at this point I have no clue about what might be going wrong - I'd be grateful for any advice.
