如何检测SQ​​L Server版本是否为Express？

Question

I have a really simple question here, but I just can't find an answer that solves it.

I have a connection string like this:

SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\DB\DB.mdf;Initial Catalog=DB;Integrated Security=True");

It works, but when I try to use it in a PC that doesn't have SQL Server Express installed, it just won't connect. It'll obviously work if I remove that "\\SQLEXPRESS" piece, I know, but I'd prefer not to do it manually on each PC I install the software. I tried to do it by using try-catch, but it's too slow and I think it isn't very recommended.

Well, I just want to know how to do it via code. Is there a simple way to do so? Will it solve the problem completely? (I mean, will it certainly work in other editions?)

Thanks in advance! (And sorry for my English)

Answer 1

Connection strings should not be hard-coded into your software.

You should place them in configuration ( web.config or app.config ) for the exact reason you are posting this question.

You can't assume there will be any version of SQL installed on the machine that your application will run on - the user may want to use a centralized server.

Answer 2

Just to clarify: A SQL server can be installed as a 'default' or a 'named' instance. I think by default, express installs as a named instance

This allows a single server machine to run multiple SQL servers

To connect to a default instance you specify the server name or IP and that's all

Server=SomeServer

To connect to a named instance you specify the server/ip + instance name separated by a backslash.

Server=SomeServer\SomeInstance

In your case you are looking to connect to a SQL instance called 'SQLEXPRESS' on the local machine. (a dot . means local machine)

You ideally want to install SQL on a server machine and use an application configuration file (App.config) to specify the connection string..

App.config supports a section called ConnectionStrings which you can add your connection string to. Then if you add a reference to System.Configuration to your project you can get hold of the connectionstring using the config manager class:

App.config:

<connectionStrings>
    <add name="YourConnectionString"
        connectionString="Server=someSqlServer\SomeInstance;Initial Catalog=SomeDB;Integrated Security=True" 
providerName="System.Data.SqlClient" />
</connectionStrings>

Use in code:

ConfigurationManager.ConnectionStrings["YourConnectionStringName"]

Answer 3

In T-SQL itself, you can inspect the edition server property:

SELECT  
   SERVERPROPERTY('edition') as 'Product Edition'

This will return something like Express Edition (64-bit) if the version you're checking is indeed an Express edition.

You can read more about all other available server properties in the relevant MSDN documentation here .

Answer 4

You should probably write something that lets your user choose the server. You can use the registry to detect SQL Server instances running locally, but that won't work if you are connecting to a network instance. See this answer about using SMO (Server Management Objects). Programmatically detect SQL Server Edition