Database explorer - Visual C# - c#

I have SQL server 2008 R2 installed with the default instance in my pc. Server name - "GED", Database name -"LOGIN".I want to access this database into my C# winform.
When i tried to add a connection from my C# database explorer (by keeping, Datasource = ".\SQLEXPRESS"),
it's giving me an
error-26-Error locating server/instance.
By keeping Datasource = ".", i am able to add the database, but it's giving me a message database not exists you want to create it?
If I try to add the database by browsing, i am getting a info that i don't have the rights. But i am the administrator.
Please help me to understand this.

Try this
You can use Environment.MachineName + "\\SQLEXPRESS" as below
var connectionString = String.Format("Data Source = {0}\\SQLEXPRESS;Initial Catalog = {1}; Integrated Security=SSPI ", Environment.MachineName, databaseName);

Related

oracle connection string with SID in c#

Hi I have to connect to an Oracle Database( about which I know a little) using a windows application.
The windows application will not necessarily be in the same system.
I just needed the connection string.
So I Used Add connection functionality in Visual Studio 2014 to test the connection and get the string.
eedb is the SID which i read in stackoverflow question
Now using above, i was able to connect to the database using this functionality and even in my visual studio server explorer all the tables of the oracle database were showing but I needed to use the connection string in the windows application.
So I used following string:
DATA SOURCE=172.31.8.21:1521/eedb;USER ID=PDB_E_GND_R
I added password too to this string as
DATA SOURCE=172.31.8.21:1521/eedb;USER ID=PDB_E_GND_R;PASSWORD=123
when i run the application i get error.
System.Data.OracleClient.OracleException: ORA-01017: invalid username/password; logon denied.
So :
Why I am getting this error. Now some may mark this question as duplicate and even point out the answer can be found in issue stackoverflow question
Coz if this was the case I would have been unable to establish connection through add connection functionality of Visual Studio at all.
Please note: I added the reference: Oracle.DataAccess
And also for a programmer like me who has very little knowledge regarding the oracle.
How I can know which connection string I have to use for a particular oracle db.
Try the following connection string EZ connect does not seem to be so EZ
data source=(DESCRIPTION =(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 172.31.8.21)(PORT = 1521)))(CONNECT_DATA =(SERVICE_NAME = eedb)));USER ID=PDB_E_GND_R;PASSWORD=123

Connect a C# MVC application to a remote SQL Server database

I have a SQL Server database located at http://192.168.10.3/MyDB. I have created a C# MVC application, and I need to know the steps to connect my application to the above database.
Is it only replacing the connection string in the web.config file ?
Data Source=?? ;Initial Catalog=??;Integrated Security=SSPI;
User ID=??;Password=pwd;
If so what am I to replace where I have placed the ?? sign ?
DataSource = 192.168.10.3
Initial Catalog = MyDB
User ID = whatever sql login you are using to access your SQL Server
Password = password for the sql login above
The other answers here are good. In addition, ConnectionStrings.com can be your friend, especially if you are going to connect to various types of databases in the future. Select the database that you need to connect to and then you'll see the different connection strings you can use for that database.
http://connectionstrings.com/sql-server-2012#sqlconnection
you can try this
create a new text document on your desktop - conn.txt
change file extension to udl (conn.udl)
double click to open the file in the first tab select appropriate provider
4 . in the second tab enter server name (ip address,port), username, password (check Allow saving password) and database name.
test connection
if the test reports success close the window.
open the file with notepad, copy everything but the provider name and paste it back to connectionString
Below is connection string you need for:
Data Source="192.168.10.3" ;Initial Catalog=MyDb;Integrated Security=SSPI;
User ID=sa (for example);Password=whatever you set before;

asp.net c# connect to local Db vs2008

I'm making an ASP.net with c# webapp using VS 2008, and I added a new sql database item to my project. I added tables to the databse. In the database explorer the test connection works. I guess I have two questions. One:In the application, how does one connect to the database using a connection string? or what connection string should I use? Second: How do I add a username and password to the database?
Right now I'm using this connection string in the web.config file, but when I run the app it times out and says it can't make a connection. The error is on the conn.open line.
add name="ReportsConnectionString" connectionString="Data Source=(local); Initial Catalog=REPORTS;Integrated Security=True" providerName="System.Data.SqlClient"
I have this code in one of my page's codebehind.
string sqlquery = "SELECT * FROM reportitems";
using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ReportsConnectionString"].ConnectionString))
{
conn.Open();
using (SqlCommand comm = new SqlCommand(sqlquery, conn))
{
using (SqlDataAdapter adapter = new SqlDataAdapter(comm))
{
DataSet ds = new DataSet();
adapter.Fill(ds, "reportitems");
DataRowCollection dra = ds.Tables["reportitems"].Rows;
foreach (DataRow dr in dra)
{
string DRZ = dr[0].ToString();
//more stuff here
}
}
}
}
Usually SqlServer Express is reachable on your local PC using this syntax for the Data Source parameter yourpcname\SQLEXPRESS. To be sure start Management Studio and look at the Server Name request.
For the security part of your question, I suppose that you don't want the Integrated Security option (Windows User), but you want a SQLServer user. In this case you could use the User ID and Password parameters for the connection string:
Data Source=MYPC\SQLEXPRESS;Initial Catalog=REPORTS;User Id=MYNAME;Password=MYPASS;
However, this works only after you have added this user to the SQLServer.
You could use the interface of Management Studio app or you could execute a script like this
USE [master]
GO
CREATE LOGIN [MYNAME] WITH PASSWORD=N'MYPASS', DEFAULT_DATABASE=[master]
GO
USE [REPORTS]
GO
CREATE USER [MYNAME] FOR LOGIN [MYNAME]
GO
The Integrated Security=True part of the connectionstring means that the server will use the credentials of the app pool running the site, and you don't need to specify username or password. The app pool identiy will, however, need to have access to your database.
Visit http://www.connectionstrings.com/ for a good primer on various ways to set the connection string for various applications. That'll show you why (local) didn't work but .\SQLEXPRESS did and how to add username and password to it. Here's an example lifted from http://www.connectionstrings.com/sql-server-2008
Data Source=myServerAddress;Initial Catalog=myDataBase;User
Id=myUsername;Password=myPassword;
As others have said, you need a SqlExpress engine running as .mdf is not a flat file. It is a SQL server express database file and you need to connect to it.
But what have not said is that a Database in your App_Data folder needs to be attached to the SqlServer instance. This step is only done once in the first connection.
In http://www.connectionstrings.com/sql-server-2008 you will find an example in the "Attach a database file, located in the data directory, on connect to a local SQL Server Express instance" section that looks like this:
Server=.\SQLExpress;AttachDbFilename=|DataDirectory|mydbfile.mdf; Database=dbname;Trusted_Connection=Yes;
Also you can read this: http://msdn.microsoft.com/en-us/library/ms247257.aspx
I believe that you will need to run some scripts and stuff like that to create a user and assign permissions to this user in this database, and then change the connection string (once the database attached), so I don't see a point in having the database in the App_Data folder. I believe it should be better if since the beginning you create your database using the SqlServer tools and connect to it from your application.

SQL Server Express 2008 connection issue; trying to connect to localhost

I've become stuck with an issue that I am sure is on- the- nose simple to fix, but this is my first time trying to connect to SQL Server Express 2008 R2. It's on my local machine, and my error is the standard:
"Cannot open database "Market" requested by the login. The login failed. Login failed for user 'KR\user'."
In SSMS, here are some of the connection properties:
Authentication Method: Windows Authentication
User Name: KR\user
Server Name: KR\SQLEXPRESS
Instance Name: SQLEXPRESS
Here is my connection string:
Data Source=localhost\SqlExpress;Initial Catalog=Market;Integrated Security=True
Here is how I'm attempting to connect via C#:
connectionString = "Data Source=localhost\\SqlExpress;Initial Catalog=Market;Integrated Security=True";
sqlConnection = new SqlConnection();
sqlConnection.ConnectionString = connectionString;
sqlConnection.Open();
Edit:My attempt with a different syntax was this connection string:
"Data Source=.\SQLExpress;AttachDbFilename='C:\Program Files\Microsoft SQL Server\MSSQL10_50.SQLEXPRESS\MSSQL\DATA\Market.mdf';Integrated Security=True;
Using it with the same calling code changes the error to:
An attempt to attach an auto-named database for file C:\Program
Files\Microsoft
SQL Server\MSSQL10_50.SQLEXPRESS\MSSQL\DATA\Market.mdf failed. A database with the same name exists, or specified file cannot
be opened, or it is located on UNC share.
Edit: I found the properly formatted connection string by right- clicking the database in database explorer, going to properties, then copy/ pasting the connection string property into my code. Thx...
You need to setup the permissions for this user on your instance of SQL Server Express.
A server login (using Windows Authentication), a database user that is attached to the login and the permissions on the databases this user will be accessing all need to be setup.
Looks like you NT security. Have checked that the "KR\user" has been granted rights on the Marketing database. Open the database "Market" > Security > Add User. Grant them DBO rights and try again.

Having trouble connecting C# executable to database file on remote computer

Using VC# I've created a staff management app that, upon its first run, is expected to query the user for the path to a (.mdf) database which will reside on a remote computer. A resulting path may be something like
string dbPath = #"P:\remoteComputer\public\StaffTool\ExamplePersonnelDatabase.mdf";
Then I'm placing this string into a connection string template as so:
string dbConnectTemplate = #"Data Source=.\SQLEXPRESS;AttachDbFilename={0};Integrated Security=True;Connect Timeout=30;User Instance=True";
string dbConnectionString = String.Format(dbConnectionTemplate,dbPath);
Then I'm attempting to connect to the database LINQ to SQL style
ManagementDBDataContext db = new ManagementDBDataContext(
dbConnectionString);
At this point, an error pop's up stating that
The file "P:\remoteComputer\public\StaffTool\ExamplePersonnelDatabase.mdf" is on a network path that is not supported for database files.
An attempt to attach an auto-named database for file P:\remoteComputer\public\StaffTool\ExamplePersonnelDatabase.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
As I am relatively new to databases, I completely do not understand this message. And obviously, the file is not on a UNC share.
Any ideas?
Jim Lamb recommended that I connect to an instance of SQL server running remotely. Considering that I'm using LINQ to SQL, what refactoring do I have to do to make this happen? Other ideas still welcome - especially "push this button and everything will work" solutions.
Another clue: A coworker said that there used to be some way to work through Control Panel->Administrative Tools->Data Sources(ODBC) so that a remote database could be viewed from my computer as if it was local. The coworker didn't know any more details besides this.
You are attempting to connect to a database file on another machine over a network connection, which isn't supported by SQL Express. You'll need to make a local copy and attach to that, or connect to an instance of SQL that's running on the same machine as the MDF file.

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