Alıntı:Ben proje ödevi hazırlarken bu konularla ilgili bayağı bir bilgi kirliliği ile karşılaşmıştım. Bir nebzede olsa C# da SQL ile yapacağınız işlemlerde temel düzeyde de olsa yararlı olması dileğiyle...
 
BAĞLANTI YAPMA
SqlConnection baganti = new SqlConnection("Data Source=abc\\SQLEXPRESS;Initial Catalog=ders;Integrated Security=True");
VERİTABANINA KAYIT EKLEME
private void button1_Click(object sender, EventArgs e)
        {
  baganti.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = baganti;
            cmd.CommandText = "insert into ogr(OGRNODTAR,CINS) VALUES(@no,@ad,@sad,@dtar,@bolum,@cins,@adres)";
            cmd.Parameters.AddWithValue("@no", textBox1.Text);
            cmd.Parameters.AddWithValue("@dtar",   dateTimePicker1.Value.ToShortDateString());
            cmd.Parameters.AddWithValue("@bolum", comboBox1.Text);
            if (radioButton1.Checked)
                cmd.Parameters.AddWithValue("@cins", "ERKEK");
            else
                cmd.Parameters.AddWithValue("@cins", "BAYAN");
            if (cmd.ExecuteNonQuery() > 0)
            {
                MessageBox.Show("KAYIT EKLENDİ");
                baganti.Close();
                verileri_goster();
            }
            else
                MessageBox.Show("KAYIT EKLENEMEDİ");
 
       
        }
 
KAYIT GÜNCELLEME
  SqlCommand cmd = new SqlCommand();
            cmd.Connection = baganti;
            string ID = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
   
            cmd.CommandText = "UPDATE OGR SET OGRNO=@noDTAR=@dtar, BOLUM=@bolum, CINS=@cins where ID=@id";
            cmd.Parameters.AddWithValue("@no", textBox1.Text);
            cmd.Parameters.AddWithValue("@dtar", dateTimePicker1.Value.ToShortDateString());
            cmd.Parameters.AddWithValue("@bolum", comboBox1.Text);
            if (radioButton1.Checked)
                cmd.Parameters.AddWithValue("@cins", "ERKEK");
            else
                cmd.Parameters.AddWithValue("@cins", "BAYAN");
 
            cmd.Parameters.AddWithValue("@id", ID);
 
            baganti.Open();
            if (cmd.ExecuteNonQuery() > 0)
            {
                MessageBox.Show("KAYIT GUNCELLENDI");
                baganti.Close();
                verileri_goster();
            }
 
 
        }
 
KAYIT SİLME
   SqlCommand cmd = new SqlCommand();
            string ID = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
 
            cmd.Connection = baganti;
            cmd.CommandText = "DELETE FROM OGR WHERE ID=" + ID;
 
            baganti.Open();
            if (cmd.ExecuteNonQuery() > 0)
            {
                MessageBox.Show("KAYIT SILINDI");
                baganti.Close();
                verileri_goster();
            }
 
        }
 
DATAGRİDDEN VERİLERİ İLGİLİ ALANLARA ÇEKME
private void dataGridView1_SelectionChanged(object sender, EventArgs e)
        {
            if (dataGridView1.SelectedRows.Count > 0)
            {
                textBox1.Text = dataGridView1.SelectedRows[0].Cells[1].Value.ToString();
                dateTimePicker1.Text = dataGridView1.SelectedRows[0].Cells[4].Value.ToString();
                comboBox1.Text =  dataGridView1.SelectedRows[0].Cells[5].Value.ToString();
                if (dataGridView1.SelectedRows[0].Cells[6].Value.ToString() == "ERKEK")
                    radioButton1.Checked = true;
                else
                    radioButton2.Checked = true;
 
                           }
        }
 
KAYITLARI LİSTELE
 
void verileri_goster()
        {
            SqlCommand cmd = new SqlCommand("select * from OGR", baganti);
            baganti.Open();
            SqlDataReader oku = cmd.ExecuteReader();
            DataTable tablo = new DataTable();
           
            tablo.Load(oku);
            dataGridView1.DataSource = tablo;
            dataGridView1.Columns[0].Visible = false;
            baganti.Close();
 
}