The name 'Database' does not exist in the

问题:

I am getting this error when I try to launch my website using WebMatrix. I have a .cs file which makes a call var db = Database.Open("dbase");.

I have a database in my project called "dbase". I have no web.config file and no imports for using WebMatrix packages since I am launching the site using WebMatrix, so I don't believe I should need them. Do I need to wrap the code in Razor tags, like @{var db = Database.Open("dbase"); } ? This causes an error for me too.

What could be causing this? Does anyone have any solutions for this?

回答1:

You need a reference to the WebMatrix.Data.dll assembly (which you probably have) and you also need a using directive for the WebMatrix.Data namespace:

using WebMatrix.Data;

That will import the Database class so you can use it without fully-qualifying the name.

It's not clear why you think you wouldn't need any "imports" (by which I assume you mean using directives like the one above) but if this is in a plain C# file, then you certainly do need them (or you need to fully-qualify type names, which is ugly).

回答2:

I ran into this issue when I was going through the w3schools stuff on ASP.NET.

Basically, the above answers are correct: you need the assembly (DLL) WebMatrix.Data, but the commenters don't tell you how to fix the problem. Here's how:

First, copy the file WebMatrix.Data.dll into your site's /bin folder.

If you're not sure where to get it, you can have WebMatrix create a new project using a database-enabled template -- say, Bakery -- and get it out of that project's bin folder. Or you can search your hard drive for the file. I have a copy in C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v2.0\Assemblies.

Then, in your ASP.NET page, import the assembly.

This is kind of a bad idea for a site you're going to have to maintain for a long time, but for the purposes of this demo, you just need to add @using WebMatrix.Data; to the top of your products page. It should end up looking something like this:

@using WebMatrix.Data;
@{
var db = Database.Open("SmallBakery"); 
var selectQueryString = "SELECT * FROM Product ORDER BY Name"; 
}

Now it should recognize the symbol "Database", and all will be well.

回答3:

You just need to get this "Microsoft.AspNet.WebPages.WebData" from the NuGet Gallery.

回答4:

In my case I had the nugget package installed but it was not finding the WebMatrix.Data. The problem was that I created a new project, instead I just created a website (file/new/WEBSITE), then the Database is found by default (I guess it's because of the type of project I created the first time)

Now it is working fine, hopefully this will help someone.