private void button1_Click(object sender, EventArgs e)
{
this.Hide();
Form21 form21 = new Form21();
form21.Show();
}
private void button2_Click(object sender, EventArgs e)
{
String connection = "Provider=OraOLEDB.Oracle;Data Source=localhost;User Id=system;Password=system;OLEDB.NET=True";
OleDbConnection obj3 = new OleDbConnection(connection);
String query1 = "select isbn from book where title = '" + textBox1.Text + "'";
OleDbCommand cm4 = new OleDbCommand(query1, obj3);
obj3.Open();
OleDbDataReader rd = cm4.ExecuteReader();
string isbn = string.Empty;
while (rd.Read())
{
isbn = rd[0].ToString();
}
obj3.Close();
String query2 = "select count(*) from copy_book where isbn = '" + isbn + "'";
OleDbCommand cm5 = new OleDbCommand(query2, obj3);
obj3.Open();
OleDbDataReader rd1 = cm5.ExecuteReader();
Int64 cps = 0;
while (rd1.Read())
{
cps = int.Parse(rd1[0].ToString());
}
obj3.Close();
if (cps > 0)
{
MessageBox.Show("Please Delete copies of the Books First");
Form21 form21 = new Form21();
form21.Show();
}
else
{
String query = "DELETE FROM book WHERE isbn ='" + isbn + "'";
obj3.Open();
try
{
OleDbCommand cm2 = new OleDbCommand(query, obj3);
cm2.ExecuteNonQuery();
MessageBox.Show("Book Deleted from Database");
}
catch (Exception ee)
{
MessageBox.Show("Error...Book not Deleted");
}
obj3.Close();
}
}
