how to use label value to fire sql query?

private void ministatement_Load(object sender, EventArgs e)
        {
             connect.Open();
SqlDataAdapter da = new SqlDataAdapter("select * from transactions where user_name='" + label2.Text + "'", connect);
            DataSet ds = new DataSet();
            da.Fill(ds, "transactions");
            BindingSource bs = new BindingSource();
            dataGridView1.AutoGenerateColumns = true;
            dataGridView1.DataSource = ds;
            dataGridView1.DataMember = "transactions".ToString();
}
}
}

private void button1_Click(object sender, EventArgs e)
        {
            ministatement mns = new ministatement();
            mns.Show();
            mns.label2.Text = label5.Text;
}