private void button1_Click(object sender, EventArgs e) { this.Hide(); Form20 form20 = new Form20(); form20.Show(); }
private void button1_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 count(*) from book where c_id=(select c_id from category where cname='" + textBox1.Text + "')"; OleDbCommand cm4 = new OleDbCommand(query1, obj3); obj3.Open(); OleDbDataReader rd = cm4.ExecuteReader(); Int64 count = 0; while (rd.Read()) { count = int.Parse(rd[0].ToString()); } obj3.Close(); if (count == 0) { String query = "delete from category where cname = '" + textBox1.Text + "'"; obj3.Open(); try { OleDbCommand cm = new OleDbCommand(query, obj3); cm.ExecuteNonQuery(); MessageBox.Show("Category Deleted from Database"); } catch (Exception ee) { MessageBox.Show("Error...Category not Deleted"); } obj3.Close(); } else { MessageBox.Show("Please Delete all records of this '" + textBox1.Text + "' category in books table "); this.Hide(); Form20 form20 = new Form20(); form20.Show(); } }