SqlDataAdapter not loading datatable - C++ - c++

Question

I have been trying to load an SQL database into a datatable in C++, however; it doesn't seem to want to work. The connection is working though, as DataReader works. Here is my code
void importDatabase() {
SqlConnection con;
SqlDataAdapter^ da;
SqlCommand cmd;
DataTable^ dt;
int count = 1;
try {
con.ConnectionString = "Data Source=MYNAME\\SQLEXPRESS;Initial Catalog=VinylRecords;Integrated Security=True";
cmd.CommandText = "SELECT * FROM Records";
cmd.Connection = %con;
con.Open();
da = gcnew SqlDataAdapter(%cmd);
dt = gcnew DataTable("Records");
Console::Write(da->ToString());
da->Fill(dt);
for (int i = 0; i < dt->Rows->Count - 1; i++) {
String^ value_string;
value_string = dt->Rows[i]->ToString();
Console::WriteLine(dt->Rows[i]->ToString());
count++;
}
cout << "There are " << count << " many records";
}
catch (Exception^ ex) {
Console::WriteLine(ex->ToString());
}
}
Please note, that I slightly altered the source name to post here, but only the first part.
What is wrong with my code?

Answer 1

So, the problem is here:
dt->Rows[i]->ToString()
Rows[i] is a Row object. And the Row class's ToString() method always prints out the fully qualified typename, which is what you are seeing. So this is technically working just fine. What you will need to do to get something useful is: you will need to access a specific column in that row and get it's value, then output that.
Something along the lines of:
foreach (DataRow dr in dt.Rows)
{
Console.Write(dr.Field<int>("ColumnOne"));
Console.Write(" | ");
Console.WriteLine(dr.Field<string>("ColumnTwo"));
}
I am not entirely sure on the syntax for accessing a specific cell inside of a DataTable when using C++\CLI. So I have provided the C# equivalent to explain why it is you were getting output of managed type names (e.g. "System.Data.DataRow") instead of the info inside of the Row's columns.
Also, I noticed you tagged this question with "mysql", but you are using the ADO.NET System.Data.SqlClient namespace. The SqlDataReader and SqlDataAdapter classes only work with TSQL (Microsoft's SQL Server databases) If you are actually connecting to a mysql database you will want to use the System.Data.OdbcDataAdapter class. You can read a little more here: https://msdn.microsoft.com/en-us/library/ms254931.aspx