[英]update not executing with query string?
我正在使用一個編輯頁面供用戶查看和更改其文本框中的數據,他們可以從主頁上的gridview訪問這些文本框。 我在自動遞增的列ProductId上使用了數據鍵,並且行數據顯示完美。 不幸的是,當我觸發單擊按鈕事件以使用這些文本框中所做的更改來更新行時,它們沒有注冊。 我已經包含了下面的代碼,但請注意,這是一個培訓項目,為了我首先學習基礎知識,我被明確禁止進行參數化。 我意識到這是安全的當務之急,但目前還沒有參數。 為了澄清並重述我的問題,當我單擊“提交”按鈕時,行數據不受文本框中輸入的更改的影響,而是恢復為原始值。 我知道這可能與查詢字符串有關,但我不知道該怎么辦。 有想法嗎?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class ViewEdit : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string x = Request.QueryString["ProductId"];
string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
string editQuery = "SELECT CustId, CustName, SicNaic, CustCity, CustAdd, CustState, CustZip, BroName, BroId, BroAdd, BroCity, BroState, BroZip, EntityType, Coverage, CurrentCoverage, PrimEx, Retention, EffectiveDate, Commission, Premium, Comments, ProductId FROM ProductInstance WHERE ProductId =" + x;
using (SqlConnection editConn = new SqlConnection(connectionString))
{
editConn.Open();
using (SqlCommand command = new SqlCommand(editQuery, editConn))
{
SqlDataReader dr = command.ExecuteReader();
dr.Read();
TextBox1.Text = dr.GetInt32(0).ToString();
TextBox2.Text = dr.GetString(1);
TextBox3.Text = dr.GetString(2);
TextBox4.Text = dr.GetString(3);
TextBox5.Text = dr.GetString(4);
TextBox6.Text = dr.GetString(5);
TextBox7.Text = dr.GetInt32(6).ToString();
TextBox8.Text = dr.GetString(7);
TextBox9.Text = dr.GetInt32(8).ToString();
TextBox10.Text = dr.GetString(9);
TextBox11.Text = dr.GetString(10);
TextBox12.Text = dr.GetString(11);
TextBox13.Text = dr.GetInt32(12).ToString();
TextBox14.Text = dr.GetString(13);
TextBox15.Text = dr.GetInt32(14).ToString();
TextBox16.Text = dr.GetInt32(15).ToString();
TextBox17.Text = dr.GetInt32(16).ToString();
TextBox18.Text = dr.GetInt32(17).ToString();
TextBox19.Text = dr.GetDateTime(18).ToString();
TextBox20.Text = dr.GetInt32(19).ToString();
TextBox21.Text = dr.GetInt32(20).ToString();
TextBox22.Text = dr.GetString(21);
}
editConn.Close();
}
}
protected void Button1_Click(object sender, EventArgs e)
{
string x = Request.QueryString["ProductId"];
string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
using (SqlConnection updateConn = new SqlConnection(connectionString))
{
updateConn.Open();
{
string updateQuery = "UPDATE ProductInstance SET CustId = '" + TextBox1.Text + "', CustName = '" + TextBox2.Text + "', SicNaic = '" + TextBox3.Text + "', CustCity = '" + TextBox4.Text + "', CustAdd = '" + TextBox5.Text + "', CustState = '" + TextBox6.Text + "', CustZip = '" + TextBox7.Text + "', BroName = '" + TextBox8.Text + "', BroId = '" + TextBox9.Text + "', BroAdd = '" + TextBox10.Text + "', BroCity = '" + TextBox11.Text + "', BroState = '" + TextBox12.Text + "', BroZip = '" + TextBox13.Text + "', EntityType = '" + TextBox14.Text + "', Coverage = '" + TextBox15.Text + "', CurrentCoverage = '" + TextBox16.Text + "', PrimEx = '" + TextBox17.Text + "', Retention = '" + TextBox18.Text + "', EffectiveDate = '" + TextBox19.Text + "', Commission = '" + TextBox20.Text + "', Premium = '" + TextBox21.Text + "', Comments = '" + TextBox22.Text + "' WHERE ProductId =" + x;
using (SqlCommand command = new SqlCommand(updateQuery, updateConn))
{
command.ExecuteNonQuery();
}
}
}
}
}
布拉索斯
發生這種情況的原因是,進行更改並將其發布回頁面后,在能夠將從表單收集的值保存回數據庫之前,將再次執行Page_Load。 而是,將使用數據庫中的值加載文本框,並覆蓋所有更改。 稍后,當Button1_Click事件發生並且確實將數據保存到數據庫時,您將使用文本框中的值更新行,這些文本框現在首先反映的是數據庫中的內容,而不是表單中提交的內容。
在此處查看ASP.NET頁面生命周期中事件的順序: http : //msdn.microsoft.com/zh-cn/library/ms178472.aspx
解決此問題的一種簡單方法是,如果不在回發中,則僅運行加載和更新文本框(在Page_Load中)的查詢:
public partial class ViewEdit : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
string x = Request.QueryString["ProductId"];
string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
string editQuery = "SELECT CustId, CustName, SicNaic, CustCity, CustAdd, CustState, CustZip, BroName, BroId, BroAdd, BroCity, BroState, BroZip, EntityType, Coverage, CurrentCoverage, PrimEx, Retention, EffectiveDate, Commission, Premium, Comments, ProductId FROM ProductInstance WHERE ProductId =" + x;
using (SqlConnection editConn = new SqlConnection(connectionString))
{
editConn.Open();
using (SqlCommand command = new SqlCommand(editQuery, editConn))
{ [...]
但是,這也意味着更改完成后,您將不再從數據庫中重新加載更改,因為此后的每個頁面事件都將作為回發(除非您進行重定向)。 由於您正在學習ASP.NET,因此建議您查看頁面生命周期並探索其他解決方案。 祝好運!
在您的Page_Load中檢查回發
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack == false)
{
string x = Request.QueryString["ProductId"];
string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString; string editQuery = "SELECT CustId, CustName, SicNaic, CustCity, CustAdd, CustState, CustZip, BroName, BroId, BroAdd, BroCity, BroState, BroZip, EntityType, Coverage, CurrentCoverage, PrimEx, Retention, EffectiveDate, Commission, Premium, Comments, ProductId FROM ProductInstance WHERE ProductId =" + x;
}
}
您應該始終在這樣的頁面上做的第一件事是檢查!IsPostBack,然后執行在代碼內呈現頁面的標准過程:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
// Add your normal code in here
}
}
然后在您的click事件中,當您完成向數據庫的插入后,重新綁定數據
protected void Button1_Click(object sender, EventArgs e)
{
// Do Insertion here
lstView.DataSource = sqlVals;
lstView.DataBind();
}
另外,請閱讀EF4或LinqToSql,因為它將使從SQL進行數據調用更加輕松和安全。
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