How to Connect a Database in asp.net using odbc? - c#

I have a system DSN.How to connect to the database in asp.net using DSN.I wanted the Connection String

Check out the link , has both DSN and DSN less ODBC connectivity using ADO.Net
http://www.easysoft.com/developer/languages/csharp/ado-net-odbc.html

One way of finding out the connection string is to create a connection in Server Explorer in Visual Studio, then check the properties of the connection and you will see a Connection String property that will give you what you need.

Related

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?

connect database with dataGridView

How can I connect my Trgovina.mdf with dataGridView?
I follow this tutorial, but it seems that program doesn't find my database.
Connection string looks like that:
string connString = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Klemen\documents\visual studio 2012\Projects\Trgovina\Trgovina\Trgovina.mdf;Integrated Security=True";
Everything else is the same as tutorial example.
Error string is An OLE DB Provider was not specified in the ConnectionString. An example would be, 'Provider=SQLOLEDB;'
Full code looks like this.
The tutorial you talk about in your question use an Access Database and thus uses the OleDB engine to reach and work with the database. Instead your connection string use the syntax reserved for SQLServer LocalDB.
You should change your objects to SqlConnection (instead of OleDbConnection), SqlCommand (instead of OleDbCommand) and so on...
With these changes you should be able to connect to the automatic instance of SqlServer LocalDB. The rest of the tutorial could work or not, depending on what is present in the MDF file used.
You trying to connect to database .mdf file, but you have a wrong provider.
An MDF is a Microsoft SQL Server database not a Jet Database like
Access (*.mdb). You cannot just connect to the flat file and read it.
You would need to mount the database in an instance of SQL Server.
You could install SQL Server 2005 Express
Source
Note: Just download MS SQL Server 2005 Express or later and you must use the System.Data.SqlClient instead of OLE DB to solve your problem.

Connecting C# app with Oracle 10g: ORA-12154: TNS:could not resolve the connect identifier specified

I am a beginner in working with databases. I am trying to access Oracle10g database from a c# application. But when I do so i get this error:
ORA-12154: TNS:could not resolve the connect identifier specified"
I'm using the following code:
string oradb = "Data Source=ORCL;User Id=system;Password=goodbye;";
OracleConnection conn = new OracleConnection(oradb); // C#
conn.Open();
Is there an error in the connection string oradb?
Start the Visual Studio, open View menu + Server Explorer.
Right mouse click on Data Connection + Add Connection + Select Oracle Database
server Name : localhost or name of your machine, set username & password and click on Test Connection to verify the above parameters. Press OK if test is succeeds.
From properties windows you can obtain connection String and it should be look a like:
Data Source=localhost;Persist Security Info=True;User ID=scott;Password=***********;Unicode=True
Oracle is just stating that it can't find the database.
If you're running a local Express Edition database, you should be able to just use XE as an instance name, and everything should already be set up, otherwise you can most easily add it to tnsnames.ora.
To find the correct tnsnames.ora to change, you can try (from the command prompt)
tnsping ORCL
That will tell you which files Oracle is using to try to find the database. If tnsping is an unknown command, you may have to search for it and go to the correct place before running it.
One you found the correct tnsnames.ora, you need to add the instance ORCL to it. There should be an existing file with examples, the syntax of that file is too complex to answer here, if you need help, Oracle has quite extensive documentation.
This is a very common oracle error. Simply put, it means that you have named the database you wish to be connected to and Oracle doesn’t know who the heck you’re talking about. I suggest 6 Steps to fix ORA-12154:
Check instance name has been entered correctly in tnsnames.ora.
There should be no control characters at the end of the instance or database name.
All paranthesis around the TNS entry should be properly terminated
Domain name entry in sqlnet.ora should not be conflicting with full database name.
If problem still persists, try to re-create TNS entry in tnsnames.ora.
At last you may add new entries using the SQL*Net Easy configuration utility.
More informations on oracle site or here : http://turfybot.free.fr/oracle/11g/errors/ORA-12154.html

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";

Create connection to database in VS2010 without SQL Client - dynamically

How to create connection to database in VS2010 without SQL Client dynamically?
I tried using ConnectionStringSettings and SqlConnection and I succeeded, but I'm not supposed to use SQL Client.
I'm using Massive.
You should be able to use System.Data.OleDb.OleDbConnection.
Use a connection string like this:
Provider=SQLOLEDB;Server=myServerAddress;Database=myDataBase;Uid=myUsername; Pwd=myPassword;
It might be that you just miss to reference System.Configuration in your project and consequently Massive cannot find the connection string in your app.config.
Following the instructions on github I could query my SQL Express database without any problems using Massive having a plain SqlClient connection string in my app.config.

Categories

Resources