c# - Insert to a SQL Server CE database

Question

How do you insert into a table in a .sdf database?

I've tried the following:

string connection = @"Data Source=|DataDirectory|InvoiceDatabase.sdf";
SqlCeConnection cn = new SqlCeConnection(connection);

try
{
   cn.Open();
}
catch (SqlCeException ex)
{
    MessageBox.Show("Connection failed");
    MessageBox.Show(ex.Message, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
    Application.ExitThread();
}

string clientName = txt_ClientName.Text;
string address = txt_ClientAddress.Text;
string postcode = txt_postcode.Text;
string telNo = txt_TelNo.Text;

string sqlquery = ("INSERT INTO Client (Name,Address,Postcode,Telephone_Number)Values(" + clientName + "','" + address + "','" + postcode + "','" + telNo + ")");
SqlCeCommand cmd = new SqlCeCommand(sqlquery, cn);

try {
  int affectedRows = cmd.ExecuteNonQuery();

  if (affectedRows > 0)
  {
     txt_ClientAddress.Text = "";
     txt_ClientName.Text = "";
     txt_postcode.Text = "";
     txt_TelNo.Text = "";
     MessageBox.Show("Client: " + clientName + " added to database. WOoo");
  }
}
catch(Exception){
    MessageBox.Show("Insert Failed.");
} 

But it doesn't seem to matter what i do it just shows "Insert Failed".

Thanks in advance.

Answer 1

You forgot opening quotation mark on the first value.

Values(" + clientName + "','"

change to:

Values('" + clientName + "','"

But this is generally a bad way to build query. Use parametrized query instead.
See: http://msdn.microsoft.com/en-us/library/system.data.sqlserverce.sqlcecommand.parameters(v=vs.80).aspx

catch(Exception ex)
{
   MessageBox.Show(ex);
} 

Will give you more info on error.