Develop Reference

Can't connect to Azure database on Sever although the connection String is right. 1042 error

Im trying to connect to MySQL database on Azure through C#. I am using MySQLConnector package for my program.
I have admin account so I can easily access to the database through Sever Explorer in Visual Studio in SSH Sever Authentication . However I can not do the same with C#. I even tried to copy the exact connection string given by Sever Explorer but I still cant connect to my database through C# . I always get the error "1042: Unable to connect to any of the specified MySQL hosts." . The connection String from Sever Explorer provide necessary param : Data Source, Inital Catalog, Persist Security Info, User ID and Password.
As I have admin account. I have also tried to copy the connection String provided from Azure Portal for ADO.net. The connection String look a bit different . For example it provide extra parameter like
TrustServerCertificate, Encrypt, MultipleActiveResultSets. However if I used this connection string, the program does not compile. Visual Studio tell me the these parameters are not supported . For example :'Option 'MultipleActiveResultSets' not supported.' etc. If I deleted those paratemters, I have the same 1042 error. Please help me, I am new. Thanks
The Connection String from Sever Explorer in Visual Studio look like this:
Data Source= ******.database.windows.net;Initial Catalog=******;Persist Security Info=True;User ID=******;Password=******
The Connection String from Azure Portal look like this:
Server=tcp:******.database.windows.net,1433;Initial Catalog=******;Persist Security Info=False;User ID=******;Password=******;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;

The Connection String from Azure Portal look like this:
Server=tcp:******.database.windows.net,1433;Initial Catalog=******;Persist Security Info=False;User ID=******;Password=******;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=False;Connection Timeout=30;
This is a SQL Server connection string. You cannot use MySqlConnector with this connection string. Are you sure you're using Azure Database for MySQL and copying the connection string from the right database?

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.

How to get the connection String from a database

I have created a database with SQL Server Management Studio, I would like to now use it in my C# application. I need the connection string?
Where can I find the connection string, and where is my database stored?
Do I have to publish it or something like that, or is it in my documents somewhere?
using (var conn = new SqlConnection("your connection string to the database"))
How do I obtain the connection string? Where can I find the connection string to copy paste into the above section?
How to I publish my database so that Visual Studio can pick it up? Then I can just pull the connection string of there?

The easiest way to get the connection string is using the "Server Explorer" window in Visual Studio (menu View, Server Explorer) and connect to the server from that window.
Then you can see the connection string in the properties of the connected server (choose the connection and press F4 or Alt+Enter or choose Properties on the right click menu).
Advanced connection string settings: when creating the connection, you can modify any of the advanced connection string options, like MARS, resiliency, timeot, pooling configuration, etc. by clicking on the "Advanced..." button on the bottom of the "Add connection" dialog. You can access this dialog later by right clicking the Data Connection, and choosing "Modify connection...". The available advanced options vary by server type.
If you create the database using SQL Server Management Studio, the database will be created in a server instance, so that, to deploy your application you'll have to make a backup of the database and deploy it in the deployment SQL Server. Alternatively, you can use a data file using SQL Server Express (localDB in SQL Server 2012), that will be easily distributed with your app.
I.e. if it's an ASP.NET app, there's an App_Datafolder. If you right click it you can add a new element, which can be a SQL Server Database. This file will be on that folder, will work with SQL Express, and will be easy to deploy. You need SQL Express / localDB installed on your machine for this to work.

A very simple way to retrieve a connection string, is to create a text file, change the extension from .txt to .udl.
Double-clicking the .udl file will open the Data Link Properties wizard.
Configure and test the connection to your database server.
Close the wizard and open the .udl file with the text editor of your choice and simply copy the connection string (without the Provider=<driver>part) to use it in your C# application.
sample udl file content
[oledb]
; Everything after this line is an OLE DB initstring
Provider=SQLNCLI11.1;Integrated Security=SSPI;Persist Security Info=False;User ID="";Initial Catalog=YOURDATABASENAME;Data Source=YOURSERVERNAME;Initial File Name="";Server SPN=""
what you need to copy from it
Integrated Security=SSPI;Initial Catalog=YOURDATABASENAME;Data Source=YOURSERVERNAME;
If you want to specify username and password you can adopt from other answers.
Tutorial: https://teusje.wordpress.com/2012/02/21/how-to-test-an-sql-server-connection/

Open SQL Server Management Studio and run following query. You will get connection string:
select
'data source=' + ##servername +
';initial catalog=' + db_name() +
case type_desc
when 'WINDOWS_LOGIN'
then ';trusted_connection=true'
else
';user id=' + suser_name() + ';password=<<YourPassword>>'
end
as ConnectionString
from sys.server_principals
where name = suser_name()

If you have installed and setup MS SQL Server and Management Studio, go to Visual Studio (Visual Studio not SQL Server Management Studio).
1] In Visual Studio go to Tools -> Connect to Database.
2] Under Server Name Select your Database Server Name (Let the list Populate if its taking time).
3] Under Connect to a Database, Select Select or enter a database name.
4] Select your Database from Dropdown.
5] After selecting Database try Test Connection.
6] If Test Connection Succeeds, Click Ok.
7] In Visual Studio go to View -> Server Explorer.
8] In Server Explorer window, Under Data Connections Select your Database. Right Click your Database -> Click Properties.
9] In Properties window you will see your Connection String.

On connectionstrings.com you can find the connection string for every DB provider. A connection string is built up with certain attributes/properties and their values. For SQL server 2008, it looks like this (standard, which is what you'll need here):
Data Source=myServerAddress;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;
on myServerAddress, write the name of your installed instance (by default it's .\SQLEXPRESS for SQL Server Express edition). Initial catalog = your database name, you'll see it in SSMS on the left after connecting. The rest speaks for itself.
edit
You will need to omit username and password for windows authentication and add Integrated Security=SSPI.

My solution was to use excel (2010).
In a new worksheet, select a cell, then:
Data -> From Other Sources -> From SQL Server
put in the server name, select table, etc,
When you get to the "Import Data" dialog,
click on Properties in the "Connection Properties" dialog,
select the "Definition" tab.
And there Excel nicely displays the Connection String for copying
(or even Export Connection File...)

If one uses the tool Linqpad, after one connects to a target database from the connections one can get a connection string to use.
Right click on the database connection.
Select Properties
Select Advanced
Select Copy Full Connection String to Clipboard
Result: Data Source=.\jabberwocky;Integrated Security=SSPI;Initial Catalog=Rasa;app=LINQPad
Remove the app=LinqPad depending on the drivers and other items such as Server instead of source, you may need to adjust the driver to suit the target operation; but it gives one a launching pad.

put below tag in web.config file in configuration node
<connectionStrings>
<add name="NameOFConnectionString" connectionString="Data Source=Server;Initial Catalog=DatabaseName;User ID=User;Password=Pwd"
providerName="System.Data.SqlClient" />
then you can use above connectionstring, e.g.
SqlConnection con = new SqlConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["NameOFConnectionString"].ToString();

The sql server database will be stored by default in the following path
<drive>:\Program Files\Microsoft SQL Server\MSSQL.X\MSSQL\Data\
, where <drive> is the installation drive and X is the instance number (MSSQL.1 for the first instance of the Database Engine). Inorder to provide the connection string you should know what is the server name of the sql server database, where you have stored followed by instance of the database server.
Generally the server name will be like the ip address of the machine where the database is attached and the default instance will be SqlExpress
A connection string contains Data Source name i.e., server name, Initial catalog i.e., database name, user id i.e., login user id of the database, password i.e., login password of the database.

Easiest way my friends, is to open the server explorer tab on visual studio 2019 (in my case), and then try to create the connection to the database. After creating a succesful connection just right click on it and go to propierties. There you will find a string connection field with the correct syntax!...This worked for me because I knew my server's name before hand....just couldn't figure out the correct syntax to run my ef scaffold...

If you created Connection Manager in your project then you can simply pull the connection string from there.
String connection = this.dts.connections["<connection_manager_name>"];
And use this connection in:
using (var conn = new SqlConnection(connection))
Please correct me if I am wrong.

SqlConnection con = new SqlConnection();
con.ConnectionString="Data Source=DOTNET-PC\\SQLEXPRESS;Initial Catalog=apptivator;Integrated Security=True";

Connect to a SQL Server database on another network via asp.net and c#

I have a customer database that is kept on a SQL Server on our local network. I would like to create a customer portal that will be on our website that is hosted through another company. How would I connect to that SQL Server database?

Give the website host access rights to the sql server. Assuming Sql Server 2008; go to your management studio and right click the server (root) in the object explorer window and go to properties. You can manage permissions from there. Also, it will show you the "server" to use in your connection string (something like [server]\SQLEXPRESS, which can be used locally and remotely).
Create a proper connection string in the website, preferably in web.config, to use for all of your connections to the database. You can then get this connection string from, say, your data layer via
ConfigurationManager.ConnectionStrings["ConnString_Name"].ConnectionString;

Aside from the correct connection string, you will also need to ensure that the website can communicate with your SQL Server. If you have firewalls, you'll need to configure ports if they are blocked.
The alternative is to create a web service that is hosted on a DMZ zone that will communicate with your sql server internally. The website (hosted by the third party) would communicate via this web service to get the data (you can setup authentication so only those with rights can use this web service). By going this route, you're not exposing your internal sql server directly.

This answer is based on some assumptions because question does not provide all the required information.
For this you need to set ConnectionString property for your connection object.
For example
Data Source=yourIP;Initial Catalog=myDataBase;User ID=myUsername;Password=myPassword;
Here is MSDN link connectionStrings
This is a example of SQLExpress connectionstring in Web.Config
<connectionStrings>
<add
name="LocalSqlServer"
connectionString="data source=.\SQLEXPRESS;Initial Catalog=myDataBase;User ID=myUsername;Password=myPassword;"
providerName="System.Data.SqlClient"
/>
</connectionStrings>

There is a Beginners guide on Code Project which is voted 5, it will give you all you need to get started.
But before you start working with the code, I suggest that you first test the connection with SQL Server management studio. make sure that you can connect and query some data, otherwise you may face some more confusion while trying to pull this off with code only at the first time.

To connect to SQL Server from C#.NET, you need to create a connection string such as below:
private SqlConnection connection; private string connectionString = #"Server=(local);Database=Embedding_SQL_Test;User ID=sa;Password=123"; connection = new SqlConnection( connectionString );
Next, you use the SqlConnection object created above to create a 'SqlCommand', as shown below:
SqlCommand cmd = new SqlCommand( "select * from Customer where CustomerID = #Cid", connection);
The SQL query shown here can be replaced by a SELECT, INSERT, UPDATE queries etc.
Next to execute the SQL queries in the database, you use the following methods: ExecuteReader - to execute SELECT queries ExecuteNonQuery - to execute INSERT, DELETE, UPDATE, and SET statements.
This is a very short description of how to connect to SQL Server database from C# and execute SQL queries in the database. For details about the connection string, the methods and their parameters check the following link: ( http://www.shahriarnk.com/Shahriar-N-K-Research-Embedding-SQL-in-C-Sharp-Java.html ) Here you will also find details about how to pass parameters to the SQL queries as well as calling stored procedures and much more.

can not open database on localnetworks

I write a win app,and i create my database on the server by codes.now every client on local network can't login to my database and this error occured
:"cannot open database "test" requested by the login.the login failed for user "farzane".
the connectionstring for to make my database is:
ConnectionString=#"Data Source=SERVER\SQLEXPRESS;Initial Catalog=master;Integrated security=SSPI;Persist Security Info=False";
and it's my connection string for open my database:
ConnectionString=#"Data Source=SERVER\SQLEXPRESS;Initial Catalog=test;Integrated security=SSPI;Persist Security Info=False";
how can give permission for logining to my database to any client with codes???
thanks in advance for any help.

I would check two things here:
Ensure that your SQL Express install allows remote connections. (Simple to check using SQL Server Studio Manager).
You are using trusted authentication in your connection string. You have to explicitly give users on your domain access on the database. You will have to this in SQL Server.

are you using a domain for the network ?
if yes then make sure that the user name has access to the SQL server
if you're using a workgroup then it won't work... just create a user on the sql server and use the sql server auth at the server and connection string

Points i concluded:
First of all the users who are going to create the database , must be authorized to use master database. So ask your admin to allow permission to farzanne.
If you(farzanne) are admin, set farzanne to create databases permission to true. Or the other users that might create dbs. Also, if you allow all users then it will be difficult to handle, your application, so be alert.
What is the need of the dynamically createing database from application. Is this a part of setup or deployment or you are creating an isolated space that is different user different database.