最近在学习.net中遇到一个关于事务处理例子。

代码如下（）

protected void Button1_Click(object sender, EventArgs e)
{
string accountStrA = TextBox1.Text.ToString();
string accountStrB = TextBox2.Text.ToString();
float fundA = (float)Convert.ToSingle(Label1.Text) - (float)Convert.ToSingle(TextBox3.Text);
float fundB = (float)Convert.ToSingle(Label2.Text) - (float)Convert.ToSingle(TextBox3.Text);

SqlConnection sqlConn = new SqlConnection();
sqlConn.ConnectionString = ConfigurationManager.AppSettings["ConnectionString"].ToString();
sqlConn.Open();
SqlTransaction myTran = sqlConn.BeginTransaction();
SqlCommand myCom = new SqlCommand();
myCom.Transaction = myTran;
try
{
myCom.CommandText = "update yinhang set jine = '" + fundA + "'where zhanghu = '" + accountStrA + "'";
myCom.ExecuteNonQuery();
myCom.CommandText = "update yinhang set jine = '" + fundB + "'where zhanghu = '" + accountStrB + "'";
myCom.ExecuteNonQuery();
myTran.Commit();
Response.Write("<script>alert('转账成功');location='Default.aspx'</script>");
}
catch (Exception ex)
{
myTran.Rollback();
Response.Write(ex.ToString());
Response.Write("<script>alert('转账错误');location='Default.aspx'</script>");
}
finally
{
sqlConn.Close();
}

其中我运行Button1_Click后就显示转账错误并说明是myCom.ExecuteNonQuery();这里的错误

所以我注释了myCom.ExecuteNonQuery();这两行代码后能显示转账成功。但是数据中的数据却没有改变。。。。。纠结中，请求各位老鸟教导一下