bank account to account transaction in c#

Question

 

 

 

 

SqlConnection con = new SqlConnection("server=.; database=bank; user id=sa; password=;");

private void button1_Click(object sender, EventArgs e)

{

int fano, tano, bal;

fano = int.Parse(textBox1.Text);

tano = int.Parse(textBox2.Text);

bal = int.Parse(textBox3.Text);

 

 

SqlCommand cmd = con.CreateCommand();

SqlTransaction transaction = null;

try

{

con.Open();

transaction = con.BeginTransaction();

cmd.Transaction = transaction;

cmd.CommandText = "update accountholder set Balance= '"+bal+"'-Balance where acno= '" + textBox1.Text + "'";

cmd.ExecuteNonQuery();

cmd.CommandText = "update accountholder set Balance= '" + bal + "'+ Balance where acno= '" + textBox2.Text + "'";

cmd.ExecuteNonQuery();

cmd.CommandText = "insert into TransferDetails (acno1,acno2,Balance) VALUES (@acno1,@acno2,@Balance)";

cmd.Parameters.AddWithValue("@acno1", textBox1.Text);

cmd.Parameters.AddWithValue("@acno2", textBox2.Text);

cmd.Parameters.AddWithValue("@Balance", textBox3.Text);

cmd.ExecuteNonQuery();

MessageBox.Show("suceess");

transaction.Commit();

}

catch(Exception ex)

{

transaction.Rollback();

MessageBox.Show(ex.Message);

}

finally

{

con.Close();

}

}

 

I wanted to transfer money from one account to another. The error occurred is SQL syntax based on where clause.i have atached the source code also. please correct the error 

cmd.CommandText = "update accountholder set Balance= '"+bal+"'-Balance where acno= '" + textBox1.Text + "'";

cmd.ExecuteNonQuery();

cmd.CommandText = "update accountholder set Balance= '" + bal + "'+ Balance where acno= '" + textBox2.Text + "'";

this line were getting error while running the code thanks