CLR20r3 System.Data.SqlClient.Sql for C# App - c#

The app works fine on my dev box but I take it to the end user's computer it gives this error. I published it and installed it on the target computer as well.
SqlConnection cs = new SqlConnection("SERVER=SERVERWITHDB;DATABASE=DATABASENAME;Trusted_Connection=True");
Is this the correct way to go about setting up a sql connection?

If you need to build the connection string inside your code (instead of configuring it in your exe.config file), you could use a SqlConnectionStringBuilder:
SqlConnectionStringBuilder connectionStringBuilder = new SqlConnectionStringBuilder
{
DataSource = "SERVERWITHDB",
InitialCatalog = "DATABASENAME",
IntegratedSecurity = true
};
SqlConnection cs = new SqlConnection(connectionStringBuilder.ToString());
You'll see that the connection string you showed in your question uses the wrong key words. A valid connection string for a SqlConnection looks like this:
SqlConnection cs = new SqlConnection("Data Source=SERVERWITHDB;Initial Catalog=DATABASENAME;Integrated Security=True");
So the keywords are:
Data Source for the database server name
Initial Catalog for the database to use
Integrated Security set to True for Windows authentication and False for SQL server authentication
User ID for the user name (SQL server authentication only)
Password for the password (SQL server authentication only)

You Need to check that the network user has access rights to SQL server (your integrated security was set to true).

Related

Connect to a SQL Server database without a set file path

I am attempting to connect to a local SQL Server database in C#.
I am currently using the following connection string:
connectionString = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\User\source\repos\majorWork\majorWork\gameStats.mdf;Integrated Security=True";
However, I do not want to use a hardcoded file path, as I wish to be able to use the application across multiple computers, where the file path will be different. How should I go about doing this?
Best way is set this connection in Web.Config file.
<Database>
<ConnectionString name="connection">Server=servername; Initial Catalog=dbname; Persist Security Info=False; User ID=username; Password=password; MultipleActiveResultSets=False; Encrypt=True; TrustServerCertificate=False; Connection Timeout=30;;</ConnectionString>
</Database>
Then add Add System.Configuration as a reference.
in C# you can call this
string constring = ConfigurationManager.ConnectionStrings["connection"].ConnectionString;
After that you can create new connection instance by passing this to
SqlConnection con = new SqlConnection(constring)
If u install SQL server express using the default instance, then you can connect using . as your server name anyone can use it with default instance as well.
1.then in visual studio, click on solution explorer
2. Connect database, follow the instruction for SQL server
3. When it gets to server name use . to connect and choose your database name which you have created already in ms SQl, then test your connection
4. After it successful, u can now click on the database name showing under solution explorer,
5.after u click the database name, at the button right corner, there will be a connection string, copy it and use
This will be declared publicly or globally
Sqlconnection con = new sqlconnection("paste the connection string");
And to use
Sqlcommand cmd = new sqlcommand("insert into......",con);
Con.open ();
Cmd.executenonquery();
Con.close();

Connection string using SQL Server authentication in C#

I am creating an Excel file in C# with SQL Server. I've tried several connection strings, but it keeps saying that it does not recognise my user ID (the ID is valid and can connect directly to SQL with this)
Can you help me, or tell me where is the error that comment?
Below I show the connections I've tried
connectionstring = "Integrated Security = SSPI;Initial Catalog='DATABASENAME'; Data Source=XXX.XXX.X.XX; ";
connectionstring = "SERVER=XXX.XXX.X.XX;DATABASE=DATABASENAME;UID=sa;PASSWORD=pass;";
connectionstring = "Persist Security Info=False;User ID=sa;Password=pass;Initial Catalog=DATABASENAME;Server=XXX.XXX.X.XX";
connectionstring = "Data Source=192.168.0.18;Initial Catalog=DATABASENAME;Persist Security Info=True;User ID=sa;Password=pass";
connectionstring = "Persist Security Info=False;Integrated Security=true;Initial Catalog=DATABASENAME;server=(XXX.XXX.X.XX)";
connectionstring = "Data Source=XXX.XXX.X.XX,1433;Network Library=DBMSSOCN; Initial Catalog=DATABASENAME;User ID=sa;Password=pass";
cnn = new SqlConnection(connectionstring);
Here is the sample connection string format
Data Source=[server];Initial Catalog=[databasename];User ID=[sa];Password=[password]
example - named instance
Data Source=localhost;Initial Catalog=master;User ID=sa;Password=sa123
in case of the default instance
Data Source=localhost\sqlexpress;Initial Catalog=master;User ID=sa;Password=sa123
if you are trying to access express version from another machine please refer and replace localhost with ip or machine name.
Navigate to C:\Windows\System32\odbcad32.exe. Go to the Drivers tab and then check to see which ODBC drivers you have installed on your system.
Then go to this website and follow the links at the top for whichever ODBC driver you have installed on your system. For C# you may or may not need the Driver= buts its usually safe.
This is the connection string which usually works for me in C# asp.net, however:
Server=[SERVER];Database=[DATABASE];Uid=[USER];Pwd=[PASSWORD]
(note how it is different than yours: Pwd= as opposed to Password=)
"HP\\ADMIN;Initial Catalog = PAY_PROCESSING_GO; User ID=sa; Password=admin#123"
this is my connection string but connection consist Keywords. How to solve this problem

Connect ODBC (without username & password) using DSN configured on windows

I have an requirement to develop windows form application in C# to connect with ODBC, select tables and its columns and at last get their data.
My exact need is to show list of DSN available on system and after selection that show its database and then show list of tables inside following with its column. Now after that I need to map all those columns with my local db column and periodically fetch data.
When I come to programming (refer below code) I see while I create an ODBC connection it ask for Username and password of database I need to connect (configured with DSN) even if I already provide those credentials while setting up DSN in control panel.
OdbcConnection conn = new OdbcConnection("Dsn=MyDSN;Uid=***;Pwd=****;");
string query = "";
OdbcCommand cmd = new OdbcCommand(query, conn);
conn.Open();
I need your help to confirm is it correct way or there is some other way also to connect db directly by DSN without using username and password as my customer is saying why I should provide credential in window application even if I already provided in DSN configuration.
I think that credentials, which you are providing in DSN Configuration wizard, are used only to fetch database list.
why I should provide credential in window application even if I already provided in DSN configuration
It is not necessary to provide credentials in DSN configuration.
Also you might want to create some service (proxy) on server, which could be configured to use specific credentials.
If you know in advance that your connection is safe, you can make your program use the stored DNS credentials (if they were previously configured) in Windows by adding the property/value "Trusted_Connection=Yes" within your config file in the label:
<connectionStrings>
<add name="myConString" connectionString="Dsn=myDsnName;Trusted_Connection=Yes" providerName="System.Data.Odbc">
</connectionStrings>
Regards.
http://www.c-sharpcorner.com/UploadFile/8ef97c/odbc-dsn-using-in-Asp-Net/
A step by step article of ODBC DSN Using in ASP.Net.
I have followed this and tested. It works fine-
my code to pull a list of customer from db -
OdbcDataAdapter da = new OdbcDataAdapter(
"SELECT * FROM [SH_Customer]",
ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
DataTable dt = new DataTable();
da.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
and my connection string in web config -
<add name="ConnectionString" connectionString="Dsn=NayansUserDsn" providerName="System.Data.Odbc" />

how to connect a remote SQLserver using widows authentication from a .net application, if possible

currently I am using this connection string inside the app.config file of the application
add name="LightSailEntities" connectionString="metadata=res://*/LightSailEntities.csdl|res://*/LightSailEntities.ssdl|res://*/LightSailEntities.msl;provider=System.Data.SqlClient;provider connection string='data source=abc.xyz.com;initial catalog=LightSail;user id=LightSail; password=yourpasswordhere;MultipleActiveResultSets=True;App=EntityFramework'" providerName="System.Data.EntityClient"
The domain of .Net application and the domain of client, using .Net application, is different from domain of SQL server. I mentioned "using widows authentication" only because of, I have the access of the server machine(means I can use Remote Desktop Connection) on which the SQL server is installed.
For Windows Auth you don't need to set the User Id and Password but you do need to include 'Integrated Security=SSPI;'
Try:
add name="LightSailEntities" connectionString="metadata=res://*/LightSailEntities.csdl|res://*/LightSailEntities.ssdl|res://*/LightSailEntities.msl;provider=System.Data.SqlClient;provider connection string='data source=dev.shopcube.com;initial catalog=LightSail;Integrated Security=SSPI;MultipleActiveResultSets=True;App=EntityFramework'" providerName="System.Data.EntityClient"
There's a bit more info here:
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring(VS.71).aspx
You have to change ConnectionString to use Integrated Security=SSPI insetad of user and password
add name="LightSailEntities"
connectionString="metadata=res://*/LightSailEntities.csdl|res://*/LightSailEntities.ssdl|res://*/LightSailEntities.msl;
provider=System.Data.SqlClient;
provider connection string='data source=dev.shopcube.com;initial catalog=LightSail;Integrated Security=SSPI;MultipleActiveResultSets=True;App=EntityFramework'"
providerName="System.Data.EntityClient"
After that, look at the Identity set for the Application Pool of you application.
That user must be authorized to access your DB using Security\Logins inside Object Explorer pan of Management Studio.
Youo can use following code:
SqlConnection conn = new SqlConnection(Configuration.DBConn);
or if you use Linq2SQL:
DBContext ctx = new DBContext(Configuration.DBConn);
where in Configuration class DBConn string contains connection string to sql ie:
Data Source=XYZ\\DEV;Initial Catalog=YOURDB;Integrated Security=True;Connect Timeout=600;connection lifetime=600
Integrated Security=True tells that you want to use windows auth.

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.

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