Question

I just want to loop through the results in the database. That’s all I am trying to do at this point! This is the error I get when I try to debug:

A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: SQL
Network Interfaces, error: 26 – Error Locating Server/Instance
Specified)

It points to this line:

// fill dataset into named table
myAdapter.Fill(myDataSet, "Sent");

Here is my whole code:

    // get connection strings from app.config
    string conString = ConfigurationManager.ConnectionStrings["Database1ConnectionString"].ConnectionString;

    // connection object
    SqlConnection myConn = new SqlConnection(conString);

    // create adapter
    SqlDataAdapter myAdapter = new SqlDataAdapter("select * from `Sent`", myConn);

    // create command builder
    SqlCommandBuilder myCommandBuilder = new SqlCommandBuilder(myAdapter);

    // create dataset
    DataSet myDataSet = new DataSet();

    // fill dataset into named table
    myAdapter.Fill(myDataSet, "Sent");

    // query using linq
    IEnumerable<DataRow> results
        = from row in myDataSet.Tables["Sent"].AsEnumerable()
          select row;

    // enumerate through results
    foreach (DataRow row in results)
    {
        MessageBox.Show(row.ToString());
    }

What can I do to fix this? Also, if anyone has an easier way to use databases in C#, I am open to your ideas because this has been ridiculous for me (manipulating a database in c#). Thank you for your help.

Update 6/29/12:

The following code works for me:

        // get connection strings from app.config
        string conString = ConfigurationManager.ConnectionStrings["Database1ConnectionString"].ConnectionString;

        // connection object
        SqlCeConnection myConn = new SqlCeConnection(conString);

        // create adapter
        SqlCeDataAdapter myAdapter = new SqlCeDataAdapter("select * from [Sent]", myConn);

        // create command builder
        SqlCeCommandBuilder myCommandBuilder = new SqlCeCommandBuilder(myAdapter);

        // create dataset
        DataSet myDataSet = new DataSet();

        // fill dataset into named table
        myAdapter.Fill(myDataSet, "Sent");

        // create new row
        DataRow newRow = myDataSet.Tables["Sent"].NewRow();

        // set field vals
        newRow["sendTo"] = sendTo;
        newRow["subject"] = subject;
        newRow["message"] = message;

        // add new row to table
        myDataSet.Tables["Sent"].Rows.Add(newRow);

        // update database
        myAdapter.UpdateCommand = myCommandBuilder.GetUpdateCommand();
        int updatedRows = myAdapter.Update(myDataSet, "Sent");
        //MessageBox.Show("There were "+updatedRows.ToString()+" updated rows");

        // close connection
        myConn.Close();

Answer 1

I wasn’t using the correct code (it didn’t have anything to do with any connection stuff). This was my first crack at trying to connect to a database in a language other than PHP. Now, I would probably use LINQ or Lambda expressions than this code. But here is what I used which worked:

    // get connection strings from app.config
    string conString = ConfigurationManager.ConnectionStrings["Database1ConnectionString"].ConnectionString;

    // connection object
    SqlCeConnection myConn = new SqlCeConnection(conString);

    // create adapter
    SqlCeDataAdapter myAdapter = new SqlCeDataAdapter("select * from [Sent]", myConn);

    // create command builder
    SqlCeCommandBuilder myCommandBuilder = new SqlCeCommandBuilder(myAdapter);

    // create dataset
    DataSet myDataSet = new DataSet();

    // fill dataset into named table
    myAdapter.Fill(myDataSet, "Sent");

    // create new row
    DataRow newRow = myDataSet.Tables["Sent"].NewRow();

    // set field vals
    newRow["sendTo"] = sendTo;
    newRow["subject"] = subject;
    newRow["message"] = message;

    // add new row to table
    myDataSet.Tables["Sent"].Rows.Add(newRow);

    // update database
    myAdapter.UpdateCommand = myCommandBuilder.GetUpdateCommand();
    int updatedRows = myAdapter.Update(myDataSet, "Sent");
    //MessageBox.Show("There were "+updatedRows.ToString()+" updated rows");

    // close connection
    myConn.Close();