asp.net中的sqldependency [英] sqldependency in asp.net

问题描述

你好

我遇到了一些代码。我现在正在返回SQL数据库（请注意 - 没有SQL SERVER MANAGEMENT STUDIO）内置到MDF文件中VISUAL STUDIO代码如下所示：

Hello
I got stuck in some code. I'm working now on the return of the SQL database (note that - no SQL SERVER MANAGEMENT STUDIO) built into the MDF file VISUAL STUDIO The code looks like this:

using (SqlCommand cmd = new SqlCommand(query, MyConnection))
{
cmd.Notification = null;
DataTable dt = new DataTable();

SqlDependency dependency = new SqlDependency(cmd);
if (MyConnection.State == ConnectionState.Closed)
MyConnection.Open();


var rdr = cmd.ExecuteReader();
dt.Load(rdr);
if (dt.Rows.Count > 0)
{
name = dt.Rows[0]["ProdName"].ToString();
price = int.Parse(dt.Rows[0]["Price"].ToString());
image = dt.Rows[0]["Images"].ToString();

}

dependency.OnChange += new OnChangeEventHandler

(dependency_OnChange);

..........

但由于某些原因它不起作用，在我看来是一个错误，上面写着：

存在同名的数据库，或指定的文件无法打开，或者它位于UNC共享上



我也是更新文件WEB.CONFIG



缓存

sqlCacheDependency pollTime =500enabled =true



add name =DataprodconnectionStringName =ConnectionString

数据库

sqlCacheDependency

缓存





........



它不起作用



谢谢

..........
But for some reason it does not work and appears to me an error that says:
"A database with the same name exists, or specified file cannot be opened, or it is located on UNC share"

I also updated the file WEB.CONFIG

caching
sqlCacheDependency pollTime="500" enabled="true"

add name="Dataprod" connectionStringName="ConnectionString"
databases
sqlCacheDependency
caching


........

And it does not work

Thanks

推荐答案

错误，存在同名的数据库... ，表明您的连接字符串存在问题。



最有可能的是，您已指定 AttachDbFileName ，但忘记指定用户实例= TRUE; 。因此，SQL已将您的MDF文件作为常规数据库附加;当它第二次尝试附加它时，数据库已经存在，并且你得到这个错误。



要解决问题，请手动分离现有数据库，然后添加您的连接字符串缺少设置。

The error, "A database with the same name exists ...", suggests that there's a problem with your connection string.

Most likely, you've specified AttachDbFileName, but forgotten to specify User Instance=true;. As a result, SQL has attached your MDF file as a regular database; when it tries to attach it a second time, the database already exists, and you get this error.

To solve the problem, manually detach the existing database, and add the missing setting to your connection string.

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