There is a delphi application in which I am trying to connect to Oracle database Using provider MSDAORA.1 but problem is coming in connecting. Oracle error message which is coming is "Oracle error occurred, but error message could not be retrieved from Oracle"
I am able to connect to database with Oracle10g client.
Connection String: Provider=MSDAORA.1;
User ID=murat;
Password = murat;
Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp) (HOST= INGPSP)(PORT=1521))(CONNECT_DATA=(SID=INGPSP)));
Persist Security Info=False;
Please provide your expert opinion what can be the reason of this?
The service name seems to be lacking in your address.
Set a tnsnames.ora file, and use the entry as data source instead of the data_source parameter you set. Follow the steps available on the faq.
Or use use connection strings like '//host[:port]/[service_name]' for your data source: //INGPSP:1521/ServiceName
For Oracle, both Microsoft and Oracle OleDB providers are known to have issue with BLOBs. If you can, use another mean of connection.
What I see that is strange is that your HOST and SID are the same. The HOST is the name of the machine on your network and the SID is the database instance on that machine. I created the following ConnectionString for the PRD3 database on machine DB19 (there are multiple databases on DB19) on our network. I was able to connect to the database successfully with real User ID and Password.
Provider=MSDAORA.1;
Password=123456;
User ID=abc;
Data Source="(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=db19)(PORT=1521))(CONNECT_DATA=(SID=prd3)))";
Persist Security Info=True
Normally the Data Source I use is the database name as defined in TNSNAMES.ORA. It is a lot less to type (fewer potential errors) and can be changed to another database without recompiling the program (such as switching between a development database and production database).
Related
I have created an Amazon RDS DB instance. I can connect to it and perform operations with SSMS. I can also bind to it using Entity Framework DB-first and generate my model. However, when I run my app, using the same connection string that was generated in the data access project, I get a "the network path was not found" error while trying to establish a connection to the DB.
Let me be clear: the db exists, the right ports are open, and the connection string is correct. I am the only one connecting to the database and the status is "available".
So what's going on? Has anyone experienced something like this?
Let me also further mention that I have already checked the usual things like internet connectivity, firewall rules, state of the database, etc.
well it started working all of a sudden. So I guess this problem will only pop up again in production or something.
I have a SQL Server 2008 R2 Express database.
I have written a Delphi application that uses a TADOConnection object to connect to the database. It works just fine on my computer. It fails to connect from other computers on the network.
It gives the error message:
Cannot open database "PeopleNetLink" requested by the login.
I have found all sorts of questions about this error message. I have found none that used SQL Server authentication and worked on one computer and not on others.
My connection string is
Provider=SQLNCLI10.1;
Integrated Security="";
Persist Security Info=False;
User ID=PNetLink;
Initial Catalog=PeopleNetLink;
Data Source=W1CNVS02\SQLEXPRESSPAY12;
Use Procedure for Prepare=1;
Auto Translate=True;
Packet Size=4096;
Initial File Name="";
Use Encryption for Data=False;
Tag with column collation when possible=False;
MARS Connection=False;
DataTypeCompatibility=0;
Trust Server Certificate=False;
Server SPN=""
Further experimentation reveals that if I log on to another computer as an admin, the program will log in successfully. This tells me that it is not using the user ID specified in the connect string. Now the question is "why not?"
This is a bit of a long-shot, as I don't have Sql Server 2008 installed, only the 2014 version. And maybe you've tried this already, but I spent hours on this problem before I found the step I was missing.
Assuming a utility like MS's PortQry shows the server's local network firewall is open and that your edition of 2008 comes with a copy of Sql Server Management Studio installed:
Start SSMS on the server,
Right-click the Sql Server's Properties
In the Properties pop-up, click the Connections tab
Check the checkbox "Allow remote connections to this server."
In some Sql Server editions, "Allow remote connections ..." is not check by default, which seems to square with marc_s's comment.
Update: Regarding your added "This tells me that it is not using the user ID specified in the connect string.":
If you open the DFM as text and hand-edit the connection string so that the "User ID" has a completely bogus value, then go back to the connection string builder, you should find two things:
The Enter information to log on to server reverts to Use a specific user name and password, so if you then click Test connection, the test unsurprisingly fails.
If you then select Use Windows NT Integrated security and click Test connection again, the test succeeds.
From 2., it is evident that the "User ID" in the connection string is ignored when using Windows authentication. That doesn't seem surprising to me, since the point of using Windows authentication is that the credentials used are those of the logged-in Windows user. You've already established that if you log in on the other computer as an admin (I assume you mean a Windows administrator account), the connection succeeds, so I'd have thought that the non-admin account needs to be added to the Sql Server's recognised users if you're wanting to connect using that ID (though I confess it's not at all clear to me whether you're actually trying to connect using Windows authentication of a specific Sql Server account).
If you're still stuck try using e.g. the Microsoft OLE DB Driver for SQL Server instead of the SQL Server Native Client. You might also single-step through this article:
https://social.msdn.microsoft.com/Forums/en-US/523c7b7e-6216-4790-87cb-945f3c1f4c5e/can-not-connect-to-microsoft-sql-server-express-2012?forum=sqlexpress
Also, google
sql server express 2008 remote "secpol.msc"
and note articles such as this one
https://social.msdn.microsoft.com/forums/sqlserver/en-US/1f5221bf-f5c3-4307-836b-a4f9dc07f02f/very-strange-remote-connection-issues
We've got a mirrored SQL server 2012 database setup on Azure VM's - two servers plus a witness, all using client certificates, with SQL logins with the same SID set.
When testing our app from a different VM, everything works as expected when we manually failover the database, there's a one second wait and then it continues to operate quite happily.
If we then do another manual failover, ie moving the principal back to the original server, the app errors and throws a 'no such host in known' error. Recycling the app pool fixes the issue, but this clearly isn't workable in production when one of the servers is updated followed by the other at some later point (both are in an availability set).
The host not known error is somewhat baffling as it was communicating with it happily before the initial failover, and will again after the app pool recycle.
Here's the connection string as it is right now, after a lot of faffing around:
"Data Source=server1,1433;Failover Partner=server2,1433;Initial
Catalog=;MultipleActiveResultSets=True;User Id=user;
Password=password; Network=dbmssocn;Connect Timeout=60; async = true;"
providerName="System.Data.SqlClient"
The app is running on .net 4.5.2, so should be up to date with hotfixes, and we're out of ideas after much Googling with Bing.
I've just solved a problem that I had that looks very similar to your problem. I'd get the host not known error whenever the database switched from the first one listed in the web.config file to the failover one. It was fine switching from the failover to the primary.
The problem that I had was that I set up the database mirroring using server names but my web server did not know the database servers by name. Once I fixed this, I was able to get the failover working smoothly both ways.
This is what I think was happening:
I set up the mirroring using the names SQL1 and SQL2 as the principal and mirror servers
I have their ip addresses in my connection string: 10.1.1.5 and 10.1.1.6
The application tries to get to the first server 10.1.1.5 and succeeds and is then told that the mirror server is SQL2
SQL1 goes down and the database is successfully switched to the mirror server.
The web application attempts to connect, fails and determines that it should try the second server.
It tries to connect to SQL2, which it doesn't know, and fails with the message that the host is unknown.
This answer would only apply to your situation if you actually put ip addresses in your web.config and that server1,1433 and server2,1433 were actually masking place-holders for the ip addresses that you actually used.
I haven't really solved the naming issue though. I just added the two database server names to the HOSTS file which isn't an acceptable situation but does prove my theory on what my problem was.
I am researching a setup just like you have and upon reading this and the response by Steve Kaye, I'm wondering if you have SQL browser running. Take a look at this article for how SQL browser comes into play:
http://blogs.msdn.com/b/spike/archive/2010/12/15/running-a-database-mirror-setup-with-the-sqlbrowser-service-off-may-produce-unexpected-results.aspx
I'm using Powershell v2.0, question is in the title. I'm having to use the old school ADOB.Connection (not the OLEDB provider) to open a Jet DB file (.mdb). The reason is simple, the ADODB.Connection exposes properties I need access to that the OLEDB provider doesn't.
I'm opening the DB via ADOB.Connection to query for some information, and then I'm trying to compact the DB using JRO.JetEngine. The issue is that I keep getting an error about the Jet DB being locked.
I'm explicitly calling Close on it, and setting the variable to $null, and still experiencing that issue. My best guess is that ADODB.Connection is using connection pooling, and so is not releasing the resources the way it should be.
According to http://support.microsoft.com/kb/191572, the call to close() should be enough, but it doesn't seem to be working.
Is there a way for me to explicitly specify no connection pooling when creating ADODB.Connection objects?
In the link you provided, it is said that calling to close returns the connection to the pool:
2.What statement returns the connection to the pool?
2.Conn.Close
You might need to destroy/dispose the ADODB.Connection object, so that it is removed from the pool, or, if you are using OLE DB as the provider, configure the OLEDB Services, as explained here:
Enabling OLE DB Resource.
Pooling Resource pooling can be enabled in
several ways:
For an ADO-based consumer, by keeping one open instance of a
Connection object for each unique user and using the OLEDB_SERVICES
connection string attribute to enable or disable pooling. By default,
ADO attempts to use pooling, but if you do not keep at least one
instance of a Connection object open for each user, there will not be
a persistent pool available to your application. (However, Microsoft
Transaction Server keeps pools persistent as long as the connections
in them have not been released and have not eventually timed out.)
this is really two questions in one I guess.
We've developed a .Net app that accesses an Oracle database, and have noticed that after changing the user's Oracle password, the app continues to work for a short time with the old password in the connection string. Presumably this is something to do with the way existing connections are pooled?
When first investigating this we tried turning off pooling in the connection string, however the app wouldn't work, throwing the error "Unable to enlist in a distributed transaction" at the point it tries to open a connection. While we probably wouldn't want to turn off connection pooling in a production app, I'm curious as to why MSDTC seems to need it?
We are using Oracle 11g (11.1.2) and latest ODP.Net (11.2 I think).
Thanks in advance
Andy
Please see some of the finding below:
For Question One: (application still connected with old DB password)
If we connect the database with connection pooling option, connection pool manager would create and maintain the number of connection sessions when first calling the open or close of OracleConnection object. (number of this connection sessions depend on "min" & "max" pool size in connection string). In Oracle, I think you could check active session like:
SELECT s.inst_id,
s.sid,
s.serial#,
p.spid,
s.username,
s.program
FROM gv$session s
JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id
WHERE s.type != 'BACKGROUND';
And according to Oracle doc, this connection pooling service will close the connection sessions after 3 minutes of in-active state. [ http://docs.oracle.com/html/E10927_01/featConnecting.htm ]
So the most possible reason could be, your application still
connected to the database by using this Pool and still connected for
a short time, even after you changed the database password.
There could be also one possibility of "Oracle Client Cache"
feature in ODP.net. But not quite sure, you can check at, [
http://www.oracle.com/technetwork/issue-archive/2008/08-jul/o48odpnet-098170.html ]
For Question Two: (why MSDTC needed)
If you are using nested Database connection in your code, it will be promoted to DTC. [ http://petermeinl.wordpress.com/2011/03/13/avoiding-unwanted-escalation-to-distributed-transactions/ ] Actually there was Oracle Service for Microsoft Transaction Server (OraMTS) act as among ODP.net, DTC, and Oracle Database.
But you didn't happend this problem (MSDTC) before disabled the connection pooling. It seems like your code is reusing the same connection out of undelining connection pool, and it might eliminate the need to promote DTC. There was similar question on StaffOverflow. [ Why isn't my transaction escalating to DTC? ]