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.
Related
We have a Server A and a Server B.
In Server A we have our ERPs made in Access and VBA.
In Server B we have an instance of SQL Server that needs to stay in that server.
Some Access databases need to link to some tables from that SQL Server instance and I don't want the password to be stored in the MSysObjects table, so I cannot manually link the tables checking the save the connection option.
I saved the connection string in a table with password obfuscation. With that connection string I re-link the tables on startup.
The instance is accessed through it's IP, not the name of the instance. If I use the name of the instance it doesn't work.
It works for me but not for other users except one.
The SQL Server instance has been properly configured to allow remote connections, the ports have been opened and rules added to firewall. If it wasn't properly configured it wouldn't work for me and the other user, so I'm pretty confident in that. The same with the connection string and the methods to stablish the connection in Access.
What I've tried:
Installing the SQL Native Client 11.0.
Installing a full SQL Server Express.
Configured the SQL Browser service to star automatically instead of being disabled.
Step 1 did not work for any user. Step 2 did work for one user but not for the rest. Step 3 did not had any effect. For me I had it installed in my machine since forever, so it doesn't apply.
If I try to do the same with a SQL Server instance in our LAN it works for every user, but not when the instance is in a remote server.
Note I have limited knowledge. Maybe I say something that does not make sense.
Ok, a few things:
Installing the SQL Native Client 11.0.
Ok, then you have to re-link the tables - choose the new driver. A refresh of the linked tables is NOT sufficent. And this ALSO means that each work station ALSO now must have native 11 instlled. And if you say decide to link using native 17 (a much newer odbc driver), then AGAIN YOU must install this native driver on each work station. While you can install multiple sql drivers on each workstation, the driver you used to link the tables MUST ALSO be installed and exist on each work station.
Installing a full SQL Server Express.
Why? What would installing a copy of sql server have to do with OTHER sql servers on other machines that you are attempting to connect to? You think installing sql server on a machine effects the sql server running say on amazon.com? So, this move makes no sense at all.
You are attempting to connect to some instance of sql server running on some other computer. Makes no sense nor will it help to install some copy of sql server that you not using, not connecting to, and that has zero to do with this issue.
Configured the SQL Browser service to star automatically instead of being disabled.
Where? The browser service is set to run and startup on the server and SAME machine where sql server is installed and running. So, yes, without question, those two sql servers A, and B most certainly MUST have the sql browser service running. That service is what allows the client computers to connect to that running instance of sql server. In the past, older (previous) versions of sql server would allow a default connection, but now in near all cases, you MUST ensure that the sql browser service is running on that computer that also has the database you are attempting to connect to.
it's worth to note that the instance is accessed through it's IP, not the name of the instance.
No, you likly have this incorrect. There are two part.
The server name - and then the "instance" of sql server running.
While you can swap out (not use) the server name, you STILL WILL NEED to specify the sql server instance.
So, you can use this format:
myservername\SQLEXPRESS
Or, you can replace the server with a IP address, but you STILL NEED the sql server instance. (by default, it is SQLEXPRESS - but you have to check what the instance of sql server database is).
192.168.1.30\SQLEXPRESS
So while you can use IP or server name - it is often more reliable to use the IP address, but that does NOT get you off the hook from having to specify the sql instance you connect to. Again, previous editions of sql server often allowed a "default" instance, and you did not in general have to specify the "instance", but now you do. And to be double clear, when using such a instance, that sql server needs to be running the sql browser service. (in fact, the browser service is what translates the incoming request to the given and correct instance of sql server).
I DON'T want the password to be stored in the MSysObjects table,
You don't have to, and in fact should NOT include the uid/password in your connection string. And in fact ZERO reason exists to do so.
What you do is execute a one time logon, and THEN link the tables without UID/password. This is not only a great idea, but it also means that your uid/password is not included in the connection strings, but also means users can't get at, or even by accident see/get the uid/password.
It also means that say someone where to launch a copy of access, and import the linked tables from this applcation. When they attempt to use the linked tables, they will NOT work.
So, then how do linked tables work without a password? (and this ALSO by the way saves you from having to re-link tables on startup!!!).
The way this works, is you in code execute a one time logon to the server on startup. That means you can either:
Prompt the user for their sql UID/password.
or
Have in code, the uid/password. (or perhaps in a text file y ou read on startup. You can thus hide, or encrypt or whatever for that uid/passwords.
Then in your startup code, you execute a one time logon. Once you done this, then all linked tables will now work - and work without having uid/password.
since you have two servers then you need to execute two logons, one for server A, and one for server B. But, once again, as long as the linked tables exist, then they will work.
Now, there are "longer" articles on how to use this logon idea, and then not have to include, or re-link your tables for the SQL uid/password.
The basic code to execute a logon is like this:
Function TestLogin(strCon As String) As Boolean
On Error GoTo TestError
Dim dbs As DAO.Database
Dim qdf As DAO.QueryDef
Set dbs = CurrentDb()
Set qdf = dbs.CreateQueryDef("")
qdf.connect = strCon
qdf.ReturnsRecords = False
'Any VALID SQL statement that runs on server will work below.
' this does assume user has enough rights to query built in
' system tables
qdf.sql = "SELECT 1 "
qdf.Execute
TestLogin = True
Exit Function
TestError:
TestLogin = False
Exit Function
End Function
Keep in mind, that ONCE you acheived a legal logon, then EVEN addtional logon attempts will return true.
Not usually a big deal, but this means you supply a valid connection to above, and if it logs on and works - then now all your linked tables (without uid/password) will work.
I note the above issue that ONCE you done the logon, then all 2nd or more times running the above will work (even if bad or incorrect!!! - DO NOT forget this tip!!!). (this can confuse the daylights out of a developer, since they execute logon, (or open a table). Then they test above routine with a BAD uid/passwords, and it works!!!
So, you have to EXIT access to clear out the password cache - no other way.
So, keep the above tips in mind.
I have a big deal: I have to connect (I just want to read data, not to write) to my customer's IBM AS/400 (aka iSeries, now IBM i) server...
I think I have all parameters needed (given me by the AS/400 programmer), but I can't figure out which driver I have to use, and if I have all software needed to to this!
I've installed IBM AS/400 ClientAccess 5.8 driver (with a patch for latest OS), and now I'm trying to configure a new Linked Server in my Sql Server 2008 R2 (x64) server.
First problem: Which driver should I use?
I have so many choices (but maybe none of these works!!):
IBM DB2 UDB for iSeries IBMDASQL OLE DB Provider
IBM DB2 UDB for iSeries IBMDA400 OLE DB Provider
IBM DB2 UDB for iSeries IBMDARLA OLE DB Provider
...or maybe other generic OLEDB/ODBC drivers?!
Second problem: Where should I put my parameters (in which fields I mean!)
In any case, in I choose a provider for my Linked Server, obviously I have to set my parameters...but I only have this:
Username of an ADMIN user
Password of the ADMIN user
AS/400 server IP address
The name of "main" archive, in which my data are stored (something like ACG_DATV2)
Third problem: How should I write my queries? How to reference an AS/400 "archive" and tables?
I don't know how to build my reading query: where are tables and views (?!) stored and how can I reference them?
Thank you in advance!
I think there are many ways to achieve what you want, but I'll try to explain what I would do in your case.
With that version of IBM ClientAccess (and also the patch), I should not have troubles in getting connected with a Sql Server 2008 R2 Linked Server if you use the correct data provider.
First of all, try to configure your linked server in this way:
Linked server name: what you want, it's just a custom name (example: MYAS400)
Provider: IBM DB2 UDB for iSeries IBMDASQL OLE DB Provider
Product name: not important, something like iSeries Access OLEDB Driver
Data source: AS/400 server IP address (example: 192.168.0.1)
Either if you configure the Linked Server using the wizard or by SQL code, the first time it will need to access the data of the AS/400 server, you'll be asked for credentials, with a typical iSeries window (look at my example).
Set your username (User ID) and the relative password, without regarding the case of the strings!!
As a general tip (but this is only related to my experience!), try to avoid special characters and upper/lower cases distinctions...
If you arrive here (no problems in the Linked Server creation), the Linked Server should work (so the first and the second problem are solved): let's build the first query!
Once the Linked Server is created, all you need is just to correctly reference the archive, the library and, of course, the correct table and the Linked Server (by name): with this informations, build a query like this (it's the usual T-SQL syntax):
SELECT
(Field1)
, (Field2)
, *
FROM (Linked Server Name).(Catalog Name).(Library).(TableName)
The only information you're probably missing is the "archive": you can easily find it browsing the Catalogs tree inside your new Linked Server, or just use iSeries Access Navigator tool!
So, in your case, I think the query should be (more or less):
SELECT
FILIO
, DTVLD
, DTVLA
, SEQZA
, CFIMP
, PADRE
, TPVLD
, CMVLD
, *
FROM MYAS400.S242DA0A.ACG_DATV2.ANLE200F
Note that S242DA0A is valid only in my case...
Remember also that:
AS/400 will probably ask you for credentials very often: also if you close and reopen SSMS.
Performance?...better to talk of something else :) ... extract the tables in your Sql Server tables and query them from there! Do it with a simple: SELECT (Fields) INTO myTable FROM (AS/400 table)
I've tried this process many times, I didn't have many troubles (once I get skilled about!)...but only for reading data (as you asked)! Never tried to update data!!!
GOOD LUCK!
I wouldn't describe myself as afraid of change - but afraid of new technologies? YES INDEED! Technologies from operating systems, to database servers just seem to become bugged, inefficient and backward the further they "progress"
MSDE 2000 (what they might call "SQL 2000 Express" in today's world)
BACKUP [MyDatabase] TO FILE 'c:\backups\mybackup.backup'
SQL 2008 EXPRESS
Wait up! Its a 'user instance' - to back it up we need to attach it to a server instance
Wait up! To attach it we need SQL Management Studio Express (78MB download)
Wait up! When we login to our .\SQLEXPRESS server instance and try to attach our database it gives us an error that literally looks like a bug in our homebrew dev project:
TITLE: Microsoft SQL Server Management Studio
Cannot show requested dialog.
------------------------------ ADDITIONAL INFORMATION:
Parameter name: nColIndex Actual value
was -1.
(Microsoft.SqlServer.GridControl)
Can someone explain how to backup a user instance of a SQL Server 2008 Express database in T-SQL code?
(sorry if this comes across like a flame at ummmm, Microsoft - I'm actually a huge fan of theirs. Just really angry about things like this! please don't vote me down...)
Um, if it's a user instance, then the simplest backup strategy is to copy the file. (whilst it's not connected to SQL Server).
If you need a more comprehensive backup strategy (e.g. transactional backups), then you really should be looking at a more comprehensive database (e.g. a "normal" one attached to a full SQL Server instance)
SOME KEY TIPS TO NOTE WHEN TRYING TO ACHIEVE USER INSTANCE BACKUP
a.) Connecting
Your connection string should look like this:
Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\MyDatabase.mdf;Integrated Security=True;User Instance=True;Database=MyDatabaseAlias
It is essential that your connection string gives the connection an alias Database=MyDatabaseAlias - this alias cannot be duplicated concurrently on the same machine or your connection may fail.
b.) Backing Up
As pointed out above, the Transact SQL to backup a database is the same on SQL MSDE/2000/2005/2008/R2 - once you have your database attached and aliased!
BACKUP DATABASE MyDatabaseAlias TO DISK = 'c:\backups\mydatabase_20101117.backup'
Whats truly amazing is the bull$h!t errors you can get because your connection string doesnt have the alias Database=MyDatabaseAlias part.
e.g. Unable to open the physical file 'c:\Code\MyProject\App_Data\MyDatabase.mdf' Operating system error 32: "32(The process cannot access the file because it is being used by another process.)".BACKUP DATABASE is terminating abnormally.
c.) Restoring
USE [master]; RESTORE DATABASE MyDatabaseAlias FROM DISK = 'c:\backups\mydatabase_20101117.backup' WITH REPLACE
Do not forget the all essential USE [master]; at the beginning of this statement (and note that its all on one line for those executing the command from a DataContext or similar) If you do, it wont be able to overwrite the existing database because you'll still be connected to it.
Once again, the assortment of totally misleading errors you might receive here, due to an invalid connection string, is endless.
I'm creating a setup using Inno-setup.
During the setup process, a SQL Server database has to be created. I want to give the user the ability to select an existing SQL Server instance (if one exists), where the database has to be created.
So, what I want to do in the setup, is to query the network (and the local machine) for SQL Server instances.Furthermore, when the user has selected an instance, I want to verify if there exists a database on that instance which has a specific name.
Anybody who knows how I can do this ? Or maybe someone could give me some pointers in the good direction?
Inno Setup supports the call of external DLL functions, so you should write a suitable helper DLL. Managed .net DLLs can only be used via a COM interface, otherwise you need an unmanaged DLL.
Valid calling conventions are: 'stdcall' (the default), 'cdecl', 'pascal' and 'register'.
Try the following native .Net library call:
using System.Data.Sql;
var instance = SqlDataSourceEnumerator.Instance;
DataTable dataTable = instance.GetDataSources();
The resultant datatable contains the following columns:
ServerName
Name of the server.
InstanceName
Name of the server instance. Blank if the server is running as the default instance.
IsClustered
Indicates whether the server is part of a cluster.
Version
Version of the server (8.00.x for SQL Server 2000, and 9.00.x for SQL Server 2005).
I need to convert a named instance of SQL server 2005, to a default instance.
Is there a way to do this without a reinstall?
The problem is, 2 out of 6 of the developers, installed with a named instance. So its becoming a pain changing connection strings for the other 4 of us. I am looking for the path of least resistance to getting these 2 back on to our teams standard setup.
Each has expressed that this is going to be, too much trouble and that it will take away from their development time. I assumed that it would take some time to resolve, in the best interest of all involved, I tried combing through configuration apps installed and didn't see anything, so I figured someone with more knowledge of the inner workings would be here.
I also wanted to convert a named instance to default - my reason was to access it with just the machine name from various applications.
If you want to access a named instance from any connection string without using the instance name, and using only the server name and/or IP address, then you can do the following:
Open SQL Server Configuration Manager
Click SQL Server Network Configuration
Click Protocols for INSTANCENAME you want to make available (i.e. SQLExpress)
Right-click TCP/IP and click Enabled
Right-click TCP/IP and go to Properties
Go to the IP Addresses tab
Scroll down to the IPAll section
Clear the field TCP Dynamic Ports (i.e. empty/blank)
Set TCP Port to 1433
Click Ok
Go to SQL Server Services
Right-click your SQL Server (INSTANCENAME) and click Restart
This will make the named instance listen on the default port. Note : You can have only one instance configured like this - no two instances can have same port on the IP All section unless the instance is a failover cluster.
As far as I know, no. One reason is the folder structure on the hard drive; they will have a name like MSSQL10.[instancename]
This is why a lot of companies store their applications' connection strings at the machine level instead of the application level.
Just take the connection string out of the source code entirely. Then have everyone put their connection string in their machine.config.
This has the added benefit of avoiding unnecessary app-specific environment logic, i.e. when you copy your application to the staging server, the staging server already "knows" what database to use.
The only way to change the instance name is to re-install - uninstall and install as default instance.
A lot of times I'll use client alias to point an application at a different sql server than the ones it's connection string is for, esp. handy when working on DTS or an application with a hard coded connection string. Have everybody use a commonly named alias, use the alias in the connection string and point the alias’s on each dev box to the to the different instances. That way you won't have to worry about if the server is the default instance or not.
You shouldn't ever really need to do this. Most software that claims to require the default instance (like Great Plains or Dynamics) doesn't actually.
If you repost with your situation (installed X, then Y, but need to accomplish Z) I bet you'll get some good workarounds.
I think you can migrate your data from Sql Server without having default instance installed. You can just specify the port number of your Sql Server instance in Oracle Sql Developer and you can connect just using the server name, not using the server name and the instance.
Like this:
connect to "MYSERVER, 1433"