How to create data base link in oracle 11 g to Access Tables.
You seem to have copied the example in the documentation without really understanding it.
The USING 'local' part of the statement is creating a link to 'the local database', where local is the service name of a database. (The example is a bit confusing, to be fair).
When the link is used it tries to interpret local as a service name, appending the current database's domain, as the docs say:
USING 'connect string'
Specify the service name of a remote database. If you specify only the
database name, then Oracle Database implicitly appends the database
domain to the connect string to create a complete service name.
Therefore, if the database domain of the remote database is different
from that of the current database, then you must specify the complete
service name.
If you're trying to create a link back into the same database - which would be a bit odd but I've seen it done in place of grant access across schemas, and that seems to be what the example is hinting at - then you can replace 'local' in the USING clause with the service name of your current database (e.g. USING 'orcl', or whatever).
You can also use a TNS alias; if your tnsnames.ora has an entry for SOME_DB which points to the SID or service name of another database, you can have USING'some_db'`. You should be able to use any connect string I think; certainly Easy Connect is allowed. There's more in the net services admin guide.
Related
I want to get the path or even the connection string of a sql.DB instance. The package I'm writing doesn't know what the database path is and the application may have multiple database files. However I need to be able to map a specific database to a specific buffered channel, and ignore any additional calls for a database the package has already seen.
The application uses the github.com/mutecomm/go-sqlcipher driver to instantiate the database, if that makes any difference.
Is it possible to discriminate between instances of sql.DB based on the file path of the source database? If so, how do I do it?
I am trying to determine the application that is using a specific session ID in an Oracle 11g database. I can find the service name of the session id using this query
select SID, SERVICE_NAME
from v$session
where SID = <sessionID here>;
Unfortunately, several applications use this service name to connect to the database. Is there another table/query that I can use to determine which application is using this session ID?
There are other columns in V$SESSION that might be useful, e.g.:
select username, osuser, logon_time, status, program, module, client_identifier, client_info
from gv$session
where sid = <sessionID here>;
However it is up to your application to set or override the last four values.
For example, a session started from SQL*Plus shows program as something like sqlplus#client_host (TNS V1-V3) and module as SQL*Plus. SQL Developer shows both values as that name. A JDBC connection will have something like 'JDBC Thin Client' for both by default, but the application can override those and/or set client_identifier and client_info if it chooses to. As can a Pro*C application, which defaults to both program and module looking something like exe_name#client_host (TNS V1-V3).
As SQL Developer is using JDBC, that is overriding both program and module with it's own value; and SQL*Plus is overriding the default module value.
So if the application using the session ID you're interested in has configured any of those values you should get a pretty good idea of what it is. And if it hasn't then you may still get clues about the kind of application (e.g. JDBC). The osuser might be useful too.
See SYS_CONTEXT and the DBMS_APPLICATION_INFO and DBMS_SESSION packages for more about how an application can set those values.
I copied a database from a live MSSQL server to my local one, and was able to log in correctly. I am having a problem however in that when it is time to call a stored procedure the Asp.Net application keeps telling me the SP does not exist, when it clearly does.
I am using windows authentication but on the server I was using credentials, could this be the problem?
Also, all of the SP's have my online username attached to their name, as in username.StoredProcedurenName.
Please help I have been trying to fix this for hours.
I just noticed that when I attempt to run the SP from the SQL Management Studio it works, but it appends the username to the SP such as:
USE [DBNAME]
GO
DECLARE #return_value int
EXEC #return_value = [username].[SPNAME]
SELECT 'Return Value' = #return_value
GO
If I remove the username, it says the same thing (SP not found). How do I get around this?
I suspect you are calling your stored procedure without specifying the schema. When calling a stored procedure (or accessing a table, view, etc) that's not in the default schema that your account is configured for, usually dbo, you need to explicitly include the schema like the sql command below
SqlCommand cmd = new SqlCommand("username.StoredProcedurenName", mySqlConnection);
It's likely what Jason said. The solution has to do with rights and ownership. When you see the SP in the SQL Management Studio, under Programmability->Stored Procedures, your SP should have a prefix like "dbo." or "GateKeeper."
If the SP has "dbo." as the prefix, the user account with which you're connecting to the DB just be part of the database owners (dbo) group, otherwise you won't have access to it. So, you can either add the user to that group, or create the stored procedure ("create procedure spBlahBlah as ..") using the account to plan to run the program under; when you call it you use "exec GateKeeper.spBlahBlah" to stipulate the Schema.StoredProcedureName.
Those are your two choices.
Apparently, using AttachDbFilename and user instance in your connection string is a bad way to connect to a DB. I'm using SQL server express on my local machine and it all seems to work fine. But what's the proper way to connect to SQL server then?
Thanks for your explanation.
Using User Instance means that SQL Server is creating a special copy of that database file for use by your program. If you have two different programs using that same connection string, they get two entirely different copies of the database. This leads to a lot of confusion, as people will test updating data with their program, then connect to a different copy of their database in Management Studio, and complain that their update isn't working. This sends them through a flawed series of wild goose chase steps trying to troubleshoot the wrong problem.
This article goes into more depth about how to use this feature, but heed the very first note: the User Instance feature has been deprecated. In SQL Server 2012, the preferred alternatives are (in this order, IMHO):
Create or attach your database to a real instance of SQL Server. Your connection string will then just need to specify the instance name, the database name, and credentials. There will be no mixup as Management Studio, Visual Studio and your program(s) will all be connecting to a single copy of the database.
Use a container for local development. Here's a great starter video by Anna Hoffman and Anthony Nocentino, and I have some other resources here, here, and here. If you're on an M1 Mac, you won't be able to use a full-blown SQL Server instance, but you can use Azure SQL Edge if you can get by with most SQL Server functionality (the omissions are enumerated here).
Use SqlLocalDb for local development. I believe I pointed you to this article yesterday: "Getting Started with SQL Server 2012 Express LocalDB."
Use SQL Server Compact. I like this option the least because the functionality and syntax is not the same - so it's not necessarily going to provide you with all the functionality you're ultimately going to want to deploy. Compact Edition is also deprecated, so there's that.
Of course if you are using a version < SQL Server 2012, SqlLocalDb is not an option - so you should be creating a real database and using that consistently. I only mention the Compact option for completeness - I think that can be almost as bad an idea as using AttachDbFileName.
EDIT: I've blogged about this here:
Bad Habits : Using AttachDBFileName
In case someone had the problem.
When attaching the database with a connection string containing AttachDBFile
with SQLEXPRESS, I noticed this connection was exclusive to the ASP.NET application that was using the database. The connection did block the access to all other processes on the file level when made with System.Data.SqlClient as provider.
In order to assure the connection to be shareable with other processes
instead use DataBase to specify the database name in your connection string
Example or connection string :
Data Source=.\SQLEXPRESS;DataBase=PlaCliGen;User ID=XXX;password=ZZZ; Connect Timeout=30
,where PlaCliGen is the name (or logical name) by which SQLEXPRESS server knows the database.
By connecting to the data base with AttachDBFile giving the path to the .mdf file
(namely : replacing DataBase = PlacliGen by AttachDBFile = c:\vs\placligen\app_data\placligen.mdf) the File was connected exclusively and no other process could connect to the database.
I have a simple access database that resides on a network drive. All of the people that need to make any modifications to this database have access on their machine, but they would like to have a read-only website just displaying the data contained in it. I set up a website and tried using the accessdatasource, and while I could connect, it had issues whenever a user had the database open in access. I swapped to using a sqldatasource with a connection string set up according to www.connectionstrings.com, but I seem to be having either the same or similar issues, depending on how I set up the string/database. Basically, the entire issue is, if the database is opened by any user, the webpage is prevented from opening the database. Is it possible to open the database read only from the webpage?
It is an access 2000 database, but everyone is using copies of access 2007, and in all of these instances, the ASP.NET user has read/write access to the network directory containing the database, and read access to the database itself.
When I use the connection string:
ConnectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\\<source>\<database>.mdb;User Id=<USER>;Password=<PASSWORD>;Mode=Share Deny Write;"
Where is not the default "admin" user, and is configured to have open/run (not open/exclusive) permissions on the database, I get the error:
Cannot start your application. The workgroup information file is missing or opened exclusively by another user.
As far as I can tell, there is no workgroup information file, but I am not really sure what I am doing there.
When is the default "admin" user, I get the error:
Could not use ''; file already in use.
If someone has the database currently open, otherwise, it works fine.
And finally, if I use the connection string:
ConnectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\\<source>\<database>.mdb;User Id=<USER>;Password=<PASSWORD>;Mode=Read;"
I get the error:
Could not lock file.
I have been googling this for the past several days now and I feel like I've just been going around in circles. Any insight at all would be appreciated.
As it's Access 2000 format there will definately have to be a workgroup file (.mdw) even if that has no security set as such. I would try the connection string whereby you also specify the workgroup location e.g:
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\mydatabase.mdb;Jet OLEDB:System Database=system.mdw;User ID=myUsername;Password=myPassword;
Furthermore, I wouldn't recommend setting the read/write properties in the connection string, instead I think you would be better to create an account in the workgroup file and only assign it read only priviledges.
Update:
This is the ODBC connection method:
Driver={Microsoft Access Driver (*.mdb)};Dbq=C:\mydatabase.mdb;Uid=Admin;Pwd=;