kako iz C# a radi sa VS2015 pristupiti bazi u MySQL

[Radomi Mihajlovic]

Imam problem kako da iz mysql baze lozinke prostupim poljusifrarad i ako postoji sifra radnika kaksnije prikazati njegovo ime. Evo poruke o gresci i deo programa. Kada startujem Foms1 dobijem ovu poruku ``Exception thrown: 'System.InvalidOperationException' in System.Data.dll
Additional information: ExecuteReader: Connection property has not been initialized.``
koristim Mysql server 5.6.29 gde se nalazi baza ili tabela LOZINKE.Evo i programa u C#
namespace EKRAN1
{
public partial class Form1 : Form
{
private int wrad1;
private MySqlConnection connection;
private object cmd;

public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
textBox2.AutoCompleteMode = AutoCompleteMode.Suggest;
textBox2.AutoCompleteSource = AutoCompleteSource.CustomSource;
var DataCollection = new AutoCompleteStringCollection();
textBox2.AutoCompleteCustomSource = DataCollection;
}

private void checkBox1_Click(object sender, EventArgs ex)
{
// citam podatke o serveru iz fileput.txt koja mora biti upisana sa NOTPAD i to sa UTF8 jer unapred ne znam gde je instaliran i moraju da budu \\ pre filePut.txt
string wput1;
var fileStream = new FileStream(@"fileput.txt", FileMode.Open, FileAccess.Read);
using (var streamReader = new StreamReader(fileStream, Encoding.UTF8))
{
wput1 = streamReader.ReadToEnd();
}
// ovo je kada znam da je server na lokalnoj masini sa programom
// server="localhost";
// database="lozinke";
// userid="root";
// password="root";
// port="3306";
// connectionString=@"server=localhost;port=3306;userid=root;password=root;";
var connectionString = "";
connectionString = (wput1);
connection = new MySqlConnection(connectionString);
OpenConnection();
}

public bool OpenConnection()
{
try
{
connection.Open();
return true;
}
catch (MySqlException ee)
{
switch (ee.Number)
{
case 0:
MessageBox.Show(" USPESNO STE SE KONEKTOVALI NA SERVER, NASTAVITE SA RADOM ");
wrad1 = 1;
return true;
// break;
case 1042:
MessageBox.Show(
" NE MOGU DA PRONADJEM SERVER / NIJE AKTIVAN SERVER, PODIGNITE SERVER PA PONOVITE KONEKTOVANJE ");
break;
}
return false;
}
}

private void textBox2_Text(object sender, EventArgs e)
{
}

private void textBox2_KeyDown ( object sender , KeyEventArgs e )
{
if (e.KeyCode == Keys.Enter)
{
string wsifrarad;
// string wimerad;
MySqlCommand cmd = null;
MySqlDataReader reader = null;
if ( wrad1==1 )
{
// var KeyChar = default ( Keys );
wsifrarad=textBox2. Text;
MessageBox. Show ( " PRVO " );
// MySqlDataAdapter i DataTable
var dataTable = new DataTable ( );
// postavljam MySqlDataReader
// pronalazi sifrarad u lozinke
var query = "SELECT lozinke.imerad INTO wimerad FROM lozinke WHERE lozinke.imerad ="+ (wsifrarad);
//ako je ostvarena connection
if (OpenConnection ( ) )
{
var myCmd = new SqlCommand ( query );
myCmd. Parameters. AddWithValue ( "ime" , wsifrarad );
var dataReader = myCmd. ExecuteReader ( );
Console. WriteLine ( "ime radnika"+dataReader[ "imerad" ] );
}
}
else


Hvala

 

[cvinker]

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[Radomi Mihajlovic]

nevredi tu nema resenja za moj problem. lupam glavu duye vreme ali ne nadjoh resenje ili je problem u mysql-u