Develop Reference

Cannot connect to SQL Server database from VS2019 on my ASP.Net project

I have been trying to open my SQL Server database in Server Explorer, and I'm always getting the following error
Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time. The duration spent while attempting to connect to this server was -[Pre-Login] initialization=18214; handshake=118555;
I've tried to fix the issue by repairing the VS2019, and that didn't work.
Edit: The database is running locally from my PC.
And this is the connection string from Web.config file:
<add name="UserEntities" connectionString="metadata=res://*/Models.UsersModel.csdl|res://*/Models.UsersModel.ssdl|res://*/Models.UsersModel.msl;provider=System.Data.SqlClient;provider connection string="data source=Mizile;initial catalog=Login;integrated security=True;multipleactiveresultsets=True;application name=EntityFramework"" providerName="System.Data.EntityClient" />

You're connection string is incorrect. If SQL Server is on your machine locally, or on your network then it CAN look something like this,
<add name="UserEntities" connectionString="Data Source=YourSqlInstanceName;Initial Catalog=YourDatabaseName;Integrated Security=True" providerName="System.Data.SqlClient" />
You can of course read MS docs about different types too.
https://learn.microsoft.com/en-us/aspnet/mvc/overview/getting-started/introduction/creating-a-connection-string

I have an answer that I posted previously here:
Connection string
Please follow the steps to get your connection string, if successful share your experience and mark as answered else let us know where you are stuck that I will edit with more help.

ServerVersion = 'conn.ServerVersion' threw an exception of type 'System.InvalidOperationException'

I've seen this error answered for other people, but I can't seem to get it to work. I'm trying to connect to a SQL Server Database project locally.
I'm getting this error thrown on Open() when I do the follow:
SqlConnection conn = null;
conn = new SqlConnection(connection)
conn.Open()
Where connection is a connection string passed from my webconfig. I've found examples online and tried these three connection strings and I get the same error every time:
<add name="TICKETING_CONNECTION" connectionString="Server=(local); DataBase=Ticketing_DB; Integrated Security=SSPI"/>
<add name="CONN"
connectionString="Data Source=localhost; Integrated Security=SSPI;Initial Catalog=Ticketing_DB"
providerName="System.Data.SqlClient" />
<add name="CONN2"
connectionString="Data Source=(local);Initial Catalog=Ticketing_DB;"
providerName="System.Data.SqlClient"
/>
Could the problem be stemming from the path of where the database is located on my machine? I've tried copying the c:\ path but didn't have any luck. I've seen some examples online use a .mdf file, but my project does not have this file either.
This is my first time trying to connect to a database project, so any help or advice would be greatly appreciated

If you are using Visual Studio try going to the Server Explorer and Right click on Data Connections and Add new connection by selecting DataSource as Microsoft SQL Server and provider as .net framework provider for SQL Server.
Under the server name check for the SQL Server if it is listed with your machine name.
Then try to provide the database details and user name and password for SQL Authentication or select windows for windows authentication. Then do a test connection. If it is fine on click of OK it will add the data connection.
Right click the properties of data connection which is newly added and navigate to properties to extract the connection string. Compare it with yours. This can help you troubleshoot the issue.

Problematic connectionstring, state closes and opens

I have a connectionstring in my xamarin android project:
`<add name="NewsPushEntities" connectionString="metadata=res://*/;provider=System.Data.SqlClient;provider connection string="Data Source=ROONEY;Initial Catalog=NewsPush;Integrated Security=True;MultipleActiveResultSets=True;Application Name=EntityFramework"" providerName="System.Data.EntityClient" />`
when I first open my project I get the state as closed.
But when I click to expand the connection in the server explorer it turns green:
However when I am trying to fetch something in my application by calling the said connectionstring it returns emptyhanded (It's a rest-service returning a menu in Json format, It works when I connect to the live server but not my local one.)
connection to live server:
<add name="NewsPushEntities" connectionString="metadata=res://*/;provider=System.Data.SqlClient;provider connection string="data source=removed;initial catalog=NewsPush;persist security info=True;user id=removed;password=removed;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
Last but not least when my state is open (after expanding my connection and it turns green) I get the following properties:
Did I bum up on the connectionstring somehow? Not sure how to get this to respond. Thanks!

If you are not getting any errors, debug your service in your local machine and use the watch window to determine if your connection string is correctly set.

Unable to load the specified metadata resource. On code first approach

Hi i am trying to create the tables using code first approach on EF5. I have created a database called "DEV_Database" on a server called "SERVER01".
After I enter "enable-migrations -contexttypename Entities -force" on package manager console I get this error "Unable to load the specified metadata resource."
I had this connection String auto generated for me by VS12, which words fine with other approaches.
Can anyone help me with this. My connection string is below.
<add name="Entities" connectionString="metadata=res://*/Models.Model1.csdl|res://*/Models.Model1.ssdl|res://*/Models.Model1.msl;provider=System.Data.SqlClient;provider connection string="data source=SERVER01;initial catalog=DEV_Database;persist security info=True;user id=USER1;password=pass;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient"/>

How to use localDb with entity framework migrations?

I have Persistence class library, which contains my DbContext class. It also contains app.config file, where I have predefined connection string like this:
<connectionStrings>
<add name="<Namespace1>.Persistence.AssessmentContext" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\AssessmentContext.mdf;Integrated Security=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
Assuming that AssesmentContext has Namespace1.Persistence namespace.
When I try to enable-migrations using PM console, it gives me such an error:
An error occurred accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file.
When I tried to debug it and put debug output into AssessmentContext ctor I found that the connection string is still using .\SQLEXPRESS data source.
Data Source=.\SQLEXPRESS;Initial Catalog=<Namespace1>.Persistence.AssessmentContext;Integrated Security=True;MultipleActiveResultSets=True
So what I am doing wrong? And why EF doesn't take my connection string from app.config?

The above connection string entry must be copied to the app.config of the executable program if you are using desktop app or copied to web.config if you are using web app.