Microsoft documentation indicates that an app using the code-first approach can simply specify the model, and the database will be created if it does not already exist.
But I want my app to store it's data in a database on the end-user's hard-disk. So I can refer to localdb (for SQL Server) in my connection string, but I still don't know what folder on the user's machine will have the database files.
How can a user back up her data files, if she doesn't know where they are?
Is there some way to ask the DbContext object where it's files are stored?
I know I can specify the path of the database when it is created via SQL, but I've been told that it is not good form to mix EF-style database interaction with non-EF database interaction (from ADO.NET).
From the Microsoft documentaion page:
User database files are stored where the user designates, typically
somewhere in the C:\Users\UserName\Documents\ folder.
So the person or setup program installing the SQL Express localdb knows where the database is.
EDIT:
To set the connection string at runtime, you can pass a connection string, instead of a connectionstring name, to your db context. You can create your connection string on your own or use a EntityConnectionStringBuilder.
// Manually build the connection string
var connectionString = "Server=(LocalDB)\MSSQLLocalDB; Integrated Security=true;AttachDbFileName=" + pathToDatabase;
var dbContext = new YourDBContext(connectionString);
Related
I am fairly beginner in here, so any help would be much appreciated :)
So, I created a SQL Database and I want to connect EasyTables to it. Apparently the automatic option has been removed and I have to do it manually.
I followed "How can I add a connection string manually" page but it lead me to nothing.
Where should i create the connection string, and what to put in the value field?
Or if there is any tutorials out there for the new way please tell me :)
Thank you a lot
You said you have followed tutorial: How can I add a connection string manually.
The Easy Table connection should like this:
SQL Database Connection String format
Data Source=tcp:{your_SQLServer},{port};Initial Catalog={your_catalogue};User ID={your_username};Password={your_password}
{your_SQLServer} Name of the server, this can be found in the
overview page for your database and is usually in the form of
“server_name.database.windows.net”.
{port} usually 1433.
{your_catalogue} Name of the database.
{your_username} User name to access your database.
{your_password} Password to access your database.
Add the connection string to your Web App
In App Service, you can manage connection strings for your application by using the Configuration option in the menu.
To add a connection string:
Click on the Application settings tab.
Click on [+] New connection string.
You will need to provide Name, Value and Type for your connection
string.
If your are adding a connection string to a SQL Azure database choose
SQLAzure under type.
If your are adding a connection to an Azure Storage account, chose
Custom under type.
NOTE If you are adding a connection string because you are planning on using the Easy API or Easy Table features, then the connection strings used by this features expect the following specific names:
Azure SQL database: MS_TableConnectionString
Azure Storage account: MS_AzureStorageAccountConnectionString
For example, this is my connection string:
When you have configured this, go to Easy table, click Add to add the table name in your Azure SQL database.
You can find that esay table has connected to my Azure SQL database now and we can see the data in the table.
Update:
You should first add the connection string in the configuration followed the format provided for you.
Then go to Easy Table, configure Easy table API:
Choose the 2:
When it done, you can add table in your SQL database, please follow my steps in above.
Note:
Your connection string name must be: MS_TableConnectionString.
Hope this helps.
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")
{
}
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.
I'm very new to SQL and made a small program where a user can input some data, click submit and the data is then stored in a table in the database.
I know want to move the application onto a friends computer, which i'm assuming has no SQL software installed, what would be the easiest way to do this, when obviously the connection string is unique to my computer and the database is stored on my computer.
You will have to install SQL Server on their machine first and foremost. Once this is done, you can obtain a relevant connection string. Note, for the 'Server name' part of the connection string, if you are using SQL Express, instead of using 'localhost', or the name of the server instance (i.e. 'MyMachine'), you would use 'localhost\SQLEXPRESS'/'MyMachine\SQLEXPRESS'.
After setting up the SQL Server instance on the new machine, to copy the required database, first detach the database to avoid any corruption. Now you are free to merely copy the file from your machine to theirs and go through the usual attachment process using SQL Server Management Studio (SQLMS).
I hope this helps.
You can use SQL CE or other file databases. On this way you need to install SQL CE(you can include SQl CE installer into your program installer) on target computer and after that you can easy copy db-file from you computer to target computer.
Also, you can use relative path to db-file from your exe file instead of fixed connection string:
string dbDirPath=Path.Combine(AppDomain.CurrentDomain.BaseDirectory,"DB" );
private const string CONN_STR_TEMPLATE = "Data Source={0};Persist Security Info=False;";
string dbFilePath = Path.Combine(dbDirPath, "my.sdf");
_connStr =String.Format(CONN_STR_TEMPLATE,dbFilePath);
You cannot simply copy your database since SQL Server database is NOT a standalone database as SQL Compact edition/MS Access.
You may configure your router to remote access SQL Server instance over the Internet by forwarding the port
Accessing SQL Server Instance through NAT
Currently I am using SQL Server CE for persisting my data for which I am providing with a .sdf and connection string mentioned in app.config pointing to this .sdf file.
Now I want to provide user with the flexibility to have the data stored in their own SQL Server database if present at there disposal.
Now I am facing the problem of how to change the connection string at runtime if user chooses to uses its own database ?
Or if restrict them to use my predefined .mdf file how to attach that in their SQL Server ?
My recommendation would be to have 2 connection strings in the configuration file (app or web). There is a special section for them intuitively called ConnectionStrings. You can then switch between them based on other settings.
Changing connection strings dynamically is actually pretty easy to do as long as you have a place to store the new settings (ie. web or app config files). If you provide a way for them to enter the server information you can use the ConfigurationManager class to update your app/web.config.
Ado.net typically has parameters on almost any db connection object that allows you to specify the connection string as an arguement. Additionally, there are helper classes that can be used to construct the connection string on the fly like the SqlConnectionStringBuilder or EntityConnectionStringBuilder. I personally love the Entity Framework as it allows you to create the database from the model itself if it does not already exist, provided you already have the connection string.