Display specific data on asp.net webpage from a microsoft sql express data table
I have been looking around the internet for a way to display specific content from a sql data table. I was hoping tha开发者_JAVA技巧t I could display the Content column according to the Id column value. alt text http://photos-h.ak.fbcdn.net/hphotos-ak-snc3/hs031.snc3/11852_1241994617732_1465331687_655971_2468696_n.jpg
If you want to have exactly one value from one single record, you can use the ExecuteScalar method of the SqlCommand class:
string title = null;
using (SqlConnection conn = new SqlConnection("your-connection-string"))
using (SqlCommand cmd = new SqlCommand(
"select ContentTitle from {put table name here} where id = 4", conn))
{
conn.Open();
title = (string)conn.ExecuteScalar();
}
if (!string.IsNullOrEmpty(title))
{
// assign title to suitable asp.net control property
}
If you want to be able to do this for various ids, do not just concatenate a new sql string. I will repeat that: do not just concatenate a new sql string. Use parameters instead:
string title = null;
using (SqlConnection conn = new SqlConnection("your-connection-string"))
using (SqlCommand cmd = new SqlCommand(
"select ContentTitle from {put table name here} where id = @id", conn))
{
SqlParameter param = new SqlParameter();
param.ParameterName = "@id";
param.Value = yourIdGoesHere;
cmd.Parameters.Add(param);
conn.Open();
title = (string)conn.ExecuteScalar();
}
if (!string.IsNullOrEmpty(title))
{
// assign title to suitable asp.net control property
}
Update
Sample aspx page. First some markup (let's say the file is called example.aspx):
<body>
<form id="Form1" runat="server">
Title: <asp:Label id="_titleLabel"
Text="{no title assigned yet}"
runat="server"/>
</form>
</body>
...and in the code-behind (that would be called example.aspx.cs; I have included only the Page_Load event for simplicity):
protected void Page_Load(object sender, EventArgs e)
{
int id;
try
{
if (int.TryParse(Request.QueryString["id"], out id))
{
_titleLabel.Text = GetContentTitle(id);
}
else
{
_titleLabel.Text = "no id given; cannot look up title";
}
}
catch (Exception ex)
{
// do something with the exception info
}
}
private static string GetContentTitle(int id)
{
using (SqlConnection conn = new SqlConnection("your-connection-string"))
using (SqlCommand cmd = new SqlCommand(
"select ContentTitle from {put table name here} where id = @id", conn))
{
SqlParameter param = new SqlParameter();
param.ParameterName = "@id";
param.Value = yourIdGoesHere;
cmd.Parameters.Add(param);
conn.Open();
return (string)conn.ExecuteScalar();
}
}
Disclaimer: the code is written directly into the answer window and not tested (I don't have access to a development environment right now) so there may be errors
加载中,请稍侯......
精彩评论