Hello to everyone! I have one problem and don't know how to solve it so I need your help. I'm building a very simple application to insert text values into a database.
private void button1_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(@"Data Source=BADRINATH-PC\SQLEXPRESS;Initial Catalog=Vremenik;Integrated Security=True;User Instance=False;");
try
{
SqlCommand cmd = new SqlCommand("INSERT INTO dbo.profesori(Ime,Prezime,VrstaProvjere,DatumProvjere) VALUES ('" + textBox1.Text + "', '" + textBox2.Text + "','" + comboBox1.Text + "', '" + dateTimePicker1.Value.Date + "')", conn);
conn.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Connection Succeful");
}
catch (SqlException ex)
{
MessageBox.Show("There is an Error" + ex);
}
finally
{
conn.Close();
MessageBox.Show("Connection Closed");
}
}
The problem is that I don't know how to check how many times is one value inserted into the specific column of the table? What to do for example if I don't want to have two same dates in my Date column? How can I solve this problem?