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Entity Framework and SQL Server database connection string

I have worked with EF for a while now and i have always used LocalDb's for storing data. I want to start working with SQL Server databases instead but I'm having some issues setting up the connection string.
https://msdn.microsoft.com/en-us/library/jj653752(v=vs.110).aspx#sse
https://www.connectionstrings.com/
and looked over google but none of the answers made it work in my case so I must be doing something wrong (some of the connections strings throw an exception others didn't but wouldn't insert anything either into the database neither)
My question is when working with EF & SQL Server, should I use both the connection string in the App.config & setting the path of the DB in the CTOR of the context (by using AppDomain.CurrentDomain.SetData("DataDirectory", path);) or is the app.config sufficient ?
I have tried the following connection strings:
Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;Trusted_Connection=True;MultipleActiveResultSets=True;
Data Source=.\GURUBEAST-PC\GURUSQL;Database=iManager;Integrated Security=True;Trusted_Connection=True;MultipleActiveResultSets=True;
Data Source=.\GURUBEAST-PC\GURUSQL;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL11.GURUSQL\MSSQL\DATA\iManager.mdf;Database=iManager;Trusted_Connection=True;MultipleActiveResultSets=True;
Data Source=.\GURUBEAST-PC\GURUSQL;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL11.GURUSQL\MSSQL\DATA\iManager.mdf;Database=iManager;Trusted_Connection=True;
Data Source=.\GURUBEAST-PC\GURUSQL;Database=iManager;Trusted_Connection=True;
Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;Integrated Security=SSPI;
Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;User id=GURUBEAST-PC\GuruBeast;
Where "iManager" is the name of the database. I use Windows auth for my SQL Server instance.
What am I doing wrong ? Should I set my path to the program files folder or the App_Data (I have seen both and tried both but both didn't work)?
Kind regards!

The Data Source key is used to find the machine on which the Sql Server instance runs.
You can have different strings for it but the most common used in a LAN environment is composed using the name of the server machine followed by an eventual instance name.
So, if your local PC is named GURUBEAST-PC and, at install time, you haven't specified any instance name, the connectionstring Data Source contains only the name of the machine GURUBEAST-PC. If you have an instance name then you should add that instance name to you Data Source key. GURUBEAST-PC\GURUSQL
This will guarantee to all the PC in the same LAN the possibility to have the same connectionstring also if the connection is made from the same PC where the SQL Server runs.
If the Data Source points at the local pc, you can use many shortcuts to represent the local PC:
(LOCAL)
localhost
.
\.
and eventually add the instance name to these shortcuts without repeating the PC name

Once you get your host name figured out, Entity Framework will generate your connection string for you. Here's a sample of what your connection string could look like if you were attempting to connect to AdventureWorks database hosted on your local instance of SQL Server 2014 aptly named sql2014.
<connectionStrings>
<add name="AdventureWorksEntities" connectionString="metadata=res://*/DataModels.AdventureWorksDb.csdl|res://*/DataModels.AdventureWorksDb.ssdl|res://*/DataModels.AdventureWorksDb.msl;provider=System.Data.SqlClient;provider connection string="data source=.\sql2014;initial catalog=AdventureWorks;persist security info=True;user id=App_AdventureWorks;password=asdasdfasdfasdf;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
</connectionStrings>
Your db context would then look something like this.Again, EF generates this for you.
public partial class AdventureWorksEntities : DbContext
{
public AdventureWorksEntities()
: base("name=AdventureWorksEntities")
{
}

Error attaching existing database entity framework code first

I have created an application using Entity Framework 6 code-first, in ASP.NET MVC 5, and am bin deploying it to my server. Everything works fine, except for the operations/controller actions that involve database usage.
I am uploading the once-generated database file from my computer to the App_Data folder of the server.
Upon deploying, I changed the connection string in my web.config file from:
connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=|DataDirectory|\aspnet-NERC_Main-20160104065223.mdf;Initial Catalog=aspnet-NERC_Main-20160104065223;Integrated Security=True"
to
connectionString="Data Source=.;AttachDbFilename=|DataDirectory|\aspnet-NERC_Main-20160104065223.mdf;Initial Catalog=aspnet-NERC_Main-20160104065223;Database=aspnet-NERC_Main-20160104065223.mdf;Trusted_Connection=Yes;Integrated Security=True;"
which throws an error of
CREATE DATABASE permission denied in database 'master'.
A probable cause of this is because the present database file is not being attached, and the entity framework is trying to generate a new database in some other, restricted directory.
I read that the AttachDbFileName is valid for SQL Server Express instances only, which in my case doesn't exist.
How can I modify the connection string so that my current, already uploaded database is utilized.
Note:
The remote server has a full installation of SQL Server 2008 R2. The server does not support user instances. My database is not password protected, and hence I've set the Integrated Security property value to True. I'll provide any other information if required.

If you have a full version of SQL Server, you cannot just use AttachDbFileName. Instead, you need to copy the .mdf (and .ldf) to the SQL Server data file location and then you need to attach the database in SQL Server Management Studio to the server instance.
From that point on, you can reference that database in your connection string using the server name, and the logical database name - something like this:
Server=.;Database=aspnet-NERC_Main-20160104065223;Integrated Security=True;
Depending on your database setup, you may or may not be able to use the Integrated Security - maybe you'll need to have a specific SQL Server login and specify that login (and its password) in your connection string instead:
Server=.;Database=aspnet-NERC_Main-20160104065223;User ID=YourUserName;Password=YourPassword
See this site here for a ton of sample of how to build valid connection strings for SQL Server.

WCF : remote SQL Server 2005 database connection

I'd like to know how to link my WCF application with a remote SQL Server database. By remote, I mean that is on the same network than me but not on the same computer/project.
I've the controll of the computer where the database is stored on.
What I've done so far : create my WCF application and try to add an ADO.NET connection. My issue : where to find the name of the server ? (and also : is it the good way to proceed ?).
Thanks !

where to find the name of the server?
Three options:
whoever "owns" the database server tells you the details, and you put them in a configuration file (or some other configuration system)
whoever "owns" the database server tells some key user the details, and the user puts them into a screen / api in the application
something like the above, but you try to discover sql servers at runtime via SqlDataSourceEnumerator (not a fan of this option, to be honest)

Conntion string should look like
Server=myServerName\myInstanceName;Database=myDataBase;User Id=myUsername;Password=myPassword;
In Place of myServerName you can use IPAdress of machine

I suggest you add connectionString in the Web.config file of the application
<add name="connectionString"
connectionString="Data Source=ServerName/PC-Name;Initial Catalog=DatabaseName;User ID=userid;Password=pass"
providerName="System.Data.SqlClient" />
Use the connection string in your code/Logic
string conn = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;

Can't connect to shared hosting database with site

Slightly at my wits end. Built an application, running fine locally. Migrated my database to MSSQL without issue, uploaded the site, can't seem to get the application to connect to the database. Any page that accesses the database I get a generic error message.
I've tried all the separate combinations of connection strings I could think of using the Godaddy recommended connection strings. Perhaps I am overlooking something simple?
I'm using Entity Framework Code-First -- My context model is called CombosContext.
<add name="CombosContext" connectionString=" Server=jelatin.db.9508732.hostedresource.com; Database=jelatin; User ID=jelatin; Password=********; Trusted_Connection=False" providerName="System.Data.SqlClient" />
<remove name="LocalSqlServer"/>
<add name="LocalSqlServer" connectionString=" Server=jelatin.db.9508732.hostedresource.com; Database=jelatin; User ID=jelatin; Password=********; Trusted_Connection=False" providerName="System.Data.SqlClient" />
Server: jelatin.db.9508732.hostedresource.com
DB name: jelatin
user: jelatin
Table: Comboes

I'm unfamiliar with GoDaddy hosted SQL, but usually a connection string to MS SQL Server uses "Data Source" instead of "Server" and "Initial Catalog" instead of "Database".
UPDATE
I didn't realize Server and Database were allowed options in the Connection String. Sorry for the confusion.
Regarding the database itself - are you letting EF create the database? Does the user have permission on GoDaddy's system to create a database?
If you have already created the database, did you populate anything? I have found that EF Code First won't correctly populate the database if the database exists and the metadata table doesn't. If you can, try copying your local database up to GoDaddy, and see if the connection works.
Finally, for your generic error message - is it coming back in a 500 error? If so, have you tried using either IE or Chrome's dev tools to inspect the response? Better error information is usually hidden in there.

Connection String management for a desktop application

I created a desktop application in C#/WPF which connects to a SQL Server 2008 instance through a constant connection string specified in code as follows (for testing purposes):
private string GetConnectionString()
{
//test
return "Data Source=[server IP]; Initial Catalog=[database name]; User ID=[user ID]; Password=[smart password];";
}
The application will be used by various users and will be deployed via ClickOnce, a .zip archive or a custom installer. It also has a separated custom login functionality by requesting an application-access username and password.
Which is the best practice to store the connection string details for my desktop application (IP, database, SQL Server user, password)? If the connection string changes over night, which is the best method to update it without forcing users to update to the latest version of my application? Users should not be able to see/intercept/decompile the connection string, so I guess I must use some sort of encryption.
Do you have any kind of suggestion for my inquiry?

Even if you compile your connection strings into the application, they still can be viewed using the Ildasm.exe (MSIL Disassembler) tool because strings are a part of assembly's metadata.
Maybe this question can help you.

In a desktop application, you can't prevent a determined user from seeing the connection string. Even if you use encryption, a determined user will be able to find and use the encryption key.

If the client is connecting to the database then the connection can be hacked.
This is a sample of connection data in App.Config
<appSettings>
<add key="dbServer" value="svr"/>
<add key="dbDataBase" value="db1"/>
<add key="dbUser" value="sharedUser"/>
<add key="dbPassword" value="easyPassword"/>
</appSettings>
Need a reference to system.configuration
string SvrName = ConfigurationManager.AppSettings["dbServer"];
string DBName = ConfigurationManager.AppSettings["dbDataBase"];
string DBUser = ConfigurationManager.AppSettings["dbUser"];
string DBPassword = ConfigurationManager.AppSettings["dbPassword"];
As for security the answer is a 2 tier application where only the secure server side code connects to the database. This code sample from server side code.
The other benefits of server side is repeated queries from the same connection can gain from indexes in memory from prior query.
You could salt and hash the password read from the AppSettings and obsfuscate the application but you would have to use a static salt so it could be hacked. It would just slow down the hacker.

You need to add an "Application Settings" file to your application. Just right click on your solution -> add -> find something similar to "app configuration". In order to do this you will need some kind of external config file to store the connection string. You could even use a simple file. If worried about people finding the file, you can always encrypt the string and decrypt it in your app.

My opinion is that the safest solution is to have a local DNS entry point to the current SQL machine and the authentication to be Windows authentication.
For example : SQLMACHINE host name pointed to 192.168.1.3 in the DNS server.
This way if the name/IP of the SQL machine changes, only the DNS server needs updated (and possibly the local DNS caches to be invalidated).
Having Windows authentication means that no password will be stored on the local machine so you can safely store the connection string in the .config file with no worries.
My 2 (euro)cents.