不知为何更新不了数据库？

[powre]

本人是个菜鸟，在做练习的时候，不知为何更新不了数据库，查了很久也查不出来。程序如下：

public static SqlDataAdapter sqldadp;
public static DataTable dt;
protected void Button2_Click1(object sender, EventArgs e)
{

SqlConnection conn = new SqlConnection();
conn.ConnectionString = "Data Source=localhost; Initial Catalog=Northwind; Integrated Security=True;"; //连接Northwind数据库
conn.Open();
sqldadp.SelectCommand.Connection = conn;
dt.Rows[0]["ContactName"] = ContactName.Text.ToString();
dt.Rows[0]["CompanyName"] = CompanyName.Text.ToString();
dt.Rows[0]["Phone"] = Phone.Text.ToString();
dt.Rows[0]["Address"] = Address.Text.ToString();
dt.AcceptChanges();
sqldadp.Update(dt);
Response.Write("数据更新成功！");

}


测试时也能显示“数据更新成功！”，但就是数据库里面的数据没有改变。我看了很久，查不出错在哪?大家帮忙看看吗？

[peng_weida]

加上 try catch 断点调试

[SQL77]

你的SQL语句呢??PRINT看看

[吕津]

帮顶。

[powre]

哦，刚才忘了发另一个控件的，所以没显示到SQL语句。现在发该页面全部的：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
public static SqlDataAdapter sqldadp;
public static DataTable dt;
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
SqlConnection conn=new SqlConnection();
conn.ConnectionString="Data Source=localhost; Initial Catalog=Northwind; Integrated Security=True;"; //连接数据库
conn.Open();
sqldadp = new SqlDataAdapter("Select CustomerID, ContactName,CompanyName,Phone,Address From Customers Where CustomerID ='"+ TCoustomerID.Text +"'" ,conn );
SqlCommandBuilder sb = new SqlCommandBuilder(sqldadp);
dt = new DataTable();
sqldadp.Fill(dt);
ContactName.Text = dt.Rows[0]["ContactName"].ToString();
CompanyName.Text = dt.Rows[0]["CompanyName"].ToString();
Phone.Text =dt.Rows[0]["Phone"].ToString();
Address.Text = dt.Rows[0]["Address"].ToString();
}


protected void Button2_Click1(object sender, EventArgs e)
{

SqlConnection conn = new SqlConnection();
conn.ConnectionString = "Data Source=localhost; Initial Catalog=Northwind; Integrated Security=True;"; //连接数据库
conn.Open();
sqldadp.SelectCommand.Connection = conn;
dt.Rows[0]["ContactName"] = ContactName.Text.ToString();
dt.Rows[0]["CompanyName"] = CompanyName.Text.ToString();
dt.Rows[0]["Phone"] = Phone.Text.ToString();
dt.Rows[0]["Address"] = Address.Text.ToString();
dt.AcceptChanges();
sqldadp.Update(dt);
Response.Write("数据更新成功！");

}
}




麻烦大家了！！

[ChargeForward]

有主键吗?

[locoasta]

你insert插入数据的时候的的 InsertCommand 咧？
你这个SqlDataAdapter在插入数据的时候获取的是 SelectCommand
数据库也不知道你要做什么啊

[locoasta]

SqlConnection conn = new SqlConnection();
        conn.ConnectionString = "Data Source=localhost; Initial Catalog=Northwind; Integrated Security=True;";    //连接数据库
        conn.Open();
        sqldadp = new SqlDataAdapter("Select CustomerID, ContactName,CompanyName,Phone,Address From Customers Where CustomerID ='" + TCoustomerID.Text + "'", conn);
        dt = new DataTable();
        sqldadp.Fill(dt); 
        sqldadp.InsertCommand = new SqlCommand("insert into tablename (ContactName,CompanyName,Phone,Address) values (@ContactName,@CompanyName,@Phone,@Address) ");
        sqldadp.InsertCommand.Parameters.Add("@ContactName", SqlDbType.NVarChar, 15, "ContactName");
        sqldadp.InsertCommand.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 15, "CompanyName");
        sqldadp.InsertCommand.Parameters.Add("@Phone", SqlDbType.NVarChar, 15, "Phone");
        sqldadp.InsertCommand.Parameters.Add("@Address", SqlDbType.NVarChar, 15, "Address");
        DataRow row = dt.NewRow;
        row["ContactName"] = "a";
        row["CompanyName"] = "b";
        row["Phone"] = "c";
        row["Address"] = "d";
        dt.Rows.Add(row);
        //dt.AcceptChanges();
        sqldadp.Update(dt);
        Response.Write("数据更新成功！"); 

没东西测试
建议你看看 msdn 的SqlDataAdapter
一直觉得这玩意不怎么好用。没用过
上面写的没数据库测试

[emoheshang]

应该是你的页面刷新了吧,把你要改的值,都还原成开始从数据库读出的值了吧

[chen_ya_ping]

添加这段代码要不然你没有UpdateCommand就不能个更新SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);

还有就是
dt.AcceptChanges();
sqldadp.Update(dt);

应该写成
sqldadp.Update(dt);
dt.AcceptChanges();
具体的信息可以参考http://www.cnblogs.com/oec2003/archive/2007/08/09/848550.html

[YL_Show]

[Quote=引用 9 楼 chen_ya_ping 的回复:]
添加这段代码要不然你没有UpdateCommand就不能个更新SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);

还有就是
dt.AcceptChanges();
sqldadp.Update(dt);

应该写成
sqldadp.Update(dt);
dt.AcceptChanges();
具体的信息可以参考http://www.cnblogs.com/oec2003/archive/2007/08/09/848550.html
[/Quote]
顶

[net_xiaojian]

sqldadp.Update(dt);
Response.Write("数据更新成功！");

这两行你怎么执行你是否明白？

--->

bool flag = sqldadp.Update(dt);

if(flag) Response.Write("数据更新成功！");
else Response.Write("数据更新失败！");