在web.config文件中輸入的連接參數只是參數。沒有實際的連接。實際上,可以在web.config中創建多個連接參數,並且可以在運行時進行實際連接。
要真正建立連接發生,你需要定義
例如,這裏的SqlDataSource的設置連接到ConnectionStrings.MyNorthwind
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT LastName FROM Employees">
</asp:SqlDataSource>
<asp:ListBox
id="ListBox1"
runat="server"
DataTextField="LastName"
DataSourceID="SqlDataSource1">
</asp:ListBox>
</form>
</body>
</html>
或在第二個例子中,他們明確地創建一個SqlConnection。這裏的連接字符串將從web.config中獲取。
private static void ReadOrderData(string connectionString)
{
string queryString =
"SELECT OrderID, CustomerID FROM dbo.Orders;";
using (SqlConnection connection = new SqlConnection(
connectionString))
{
SqlCommand command = new SqlCommand(
queryString, connection);
connection.Open();
SqlDataReader reader = command.ExecuteReader();
try
{
while (reader.Read())
{
Console.WriteLine(String.Format("{0}, {1}",
reader[0], reader[1]));
}
}
finally
{
// Always call Close when done reading.
reader.Close();
}
}
}
這裏是你的web.config
<configuration>
<connectionStrings>
<add name="ApplicationServices"
connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>
我不明白的問題可以找到一個連接字符串的例子。如果可以連接到數據庫,則連接已建立。你遇到特定問題嗎? – 2010-10-23 21:27:49
不,我只是想知道,簡單地將connectionstring/UID/password/databaseName添加到web.config文件中會在asp.net中打開一個連接?還是我必須明確寫一個C#代碼來建立它? – zack 2010-10-23 21:32:08