Local SQL Server connection fail

Question

I'm trying to connect to a local SQL Server database file and do not know if connection string is right:

SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\ma\Documents\mydb.mdf;Integrated Security=True;");
SqlDataAdapter sda = new SqlDataAdapter("SELECT plataform FROM plataforms", con);

DataSet myDataSet = new DataSet();
sda.Fill(myDataSet);

I have such code wrapped in a try catch and always throws this exception:

Reference to object not established as an instance of an object

What's wrong?

EDIT:

Sorry, I have been commenting code to see what line arises such error and it's the following:

DataRowCollection drc = myDataSet.Tables["plataforms"].Rows;

Sorry, I made a wrong question.

@Arulkumar It shows: Reference to object not established as an instance of an object — Apalabrados, Jun 01 '17 at 07:08
Executes the `SELECT plataform FROM plataforms` in your SQL Server Management studio returns any data? — Arulkumar, Jun 01 '17 at 07:10
There is no need to execute that query in SSMS, the error is not the SERVER error — sepupic, Jun 01 '17 at 07:19
Possible duplicate of [What is a NullReferenceException, and how do I fix it?](https://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Arulkumar, Jun 01 '17 at 07:37
If you have only a single result set anyway - then I'd recommend just using `DataTable` (instead of `DataSet`) to put the results into — marc_s, Jun 01 '17 at 07:53

Jaycey · Answer 1 · 2017-06-01T07:38:29.633

0

I think You must open connection before Fill

SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\ma\Documents\mydb.mdf;Integrated Security=True;");
SqlDataAdapter sda = new SqlDataAdapter("SELECT plataform FROM plataforms", con);

SqlDataAdapter dAdapter = new SqlDataAdapter();
dAdapter.SelectCommand = sda;
DataSet myDataSet = new DataSet();
try {
      con.Open();
      sda.Fill(myDataSet);
   } catch (Exception ex) {
      throw (ex);
   } finally {
      con.Close();
   }

you can try this code.

edited Jun 01 '17 at 07:38

answered Jun 01 '17 at 07:25

Jaycey

18
3

Hi, I included the open connection and arises the same error. – Apalabrados Jun 01 '17 at 07:27
No you don't - the `SqlDataAdapter.Fill()` method will itself open the connection, if necessary. – marc_s Jun 01 '17 at 07:52

Local SQL Server connection fail

1 Answers1