i have a security application that stores its data in a access database.now i'm required to
make a realtime synchronization (replication) between that access database and a new database in sql server 2005. these two database are the same.
any suggestion?!
i don't know how to do it using a windows service or not. i need exact technical answer.
Mostly, I would suggest you use a windows service to periodically check the MS Access db, and attempt to synchronize it with the Sql database.
This will allow you to remove the Human factor, and have this task run periodically to sync the dbs.
Have a look at
Creating a Basic Windows Service in
C#
Creating a Windows Service in C#
Also
Connect to Microsoft Access .mdb
database using C#
Beginners guide to accessing SQL
Server through C#
SQL server has built-in replication functionality that you get for free, so you don't need to worry about copying rows & tracking changes. There are several types of SQL replication that are used for different situations, such as merge replication, snapshot replication, and transactional replication. This last one, transactional replication sounds like what you want. Merge replication is used when you have users that might disconnect, go away and return later to synchronize (like remote users). Transactional replication is used where the subscribers and publisher are reliably connected. Snapshot replication generates a new snapshot each time synchronization occurs, and doesn't think about changes to the data. Read the MSDN documentation and find which of these types is appropriate for your situation.
Using these replication methods will require that you set up your tables in a SQL server or express instance - you can use that to synchronize with your SQL server and keep everything else Access as the front end. I think you want to follow astander's suggestion and use a windows service to trigger synchronization. However you can set up the Windows Synchronization Manager to automatically try to synchronize at startup, shutdown, when the computer is idle, etc. If you need finer control over triggering the synchronization then perhapse use a Windows app or service as astander suggested.
Related
In SQL Server, What is enable_broker?
What is the risk?
SQL Table Dependency wants that.
1) https://learn.microsoft.com/en-us/sql/database-engine/configure-windows/sql-server-service-broker?view=sql-server-2017
SQL Server Service Broker provides native support for messaging and
queuing applications in the SQL Server Database Engine. This makes it
easier for developers to create sophisticated applications that use
the Database Engine components to communicate between disparate
databases. Developers can use Service Broker to easily build
distributed and reliable applications.
2) https://www.sqlservercentral.com/Forums/Topic818423-146-1.aspx
One risk being if there are already service brokers setup to use that
DB they will probably break, and any live connections will be killed
and rollback.
3) Sql Dependency with Service Broker
It's not necessary but if you want to see changes you need it or you can use an other service like periodic polling
Be careful using the SqlDependency class to monitor changes in the
database tables - it has the problems with the memory leaks.
I hope it will help you !
I have a calendar-type WPF program that is used to assign the workload to a team. The events are stored in an Access database and the program is accessed by one person at a time by remotely connection to a computer. The team has grown and multiple people would need to access the program simultaneously. I can install the program on several computers, but where should I move the database? On a software like Dropbox/Onedrive, on a SQL online host? Thanks.
You can use a SQL Server on many Cloud platforms (though I am not sure Dropbox can host SQL Server natively). Azure (Microsoft cloud) is a very mature solution. You still should verify, now that multiple users will be managing data, that the database is backed up a regular basis and that any updates to data should be done within transactions that your code should be aware of. 'Aware of' means that if there is a conflict your code should either resubmit or notify the user that the insert/update/delete failed.
I have an installation which has two SCADA (Intouch) HMIs and I want to save the data in an SQL Server database which will be in another computer. To be as sure as possible that I have an operating database I'm going to set a SQL Server mirroring. So I will have 2 SQL server databases with a distributor. About this I don't have any doubt. To make it easy to understand I've made an image with the architecture of the system.
Architecture.
My doubt is how do I configure the Alarm DB Logger to make it point, automatically, to the secondary database in case that the principal database is down for any unknown failover.
PS: I don't know if it's even possible.
Configure it the database in Automatic failover. The connection are handled automatically in case of a failover. Read on Mirroring EndPoints
The below Links should have more than enough information.
https://learn.microsoft.com/en-us/sql/database-engine/database-mirroring/role-switching-during-a-database-mirroring-session-sql-server
https://learn.microsoft.com/en-us/sql/database-engine/database-mirroring/the-database-mirroring-endpoint-sql-server
The AlarmDBLogger reads its configuration from the registry, so you could try the following:
Stop AlarmLogger
Change ServerName in registry [HKLM].[Software].[Wonderware].[AlarmLogger].[SQLServer]
Start AlarmLogger
But what about the two InTouch-nodes? What if one of those fails? You would have to make sure one of them logs alarms, and that they don't log duplicates!
The standard controls and activex for alarms use a specific view in the alarm database. You cannot change that behaviour, but you can script a server change in InTouch or System Platform.
Keep in mind that redundancy needs to be tested, and should only be implemented if 100% uptime is necessary. In many cases you will be creating new problems to solve instead of solving an actual problem.
I would like to know what are best practices for using SQL Server replication on a SQL Server instance that may have other application databases that may also use replication. That is, our product needs to play well with other users of the instance.
The product currently uses SQL Server replication to create a copy database used for reporting. It is always the sole user of the SQL Server instance. But we now need to document and test (regulatory requirements) how the product can share the instance.
I'm making the assumption here that we still need replication as we do not see another way to isolate reporting load from the application's database.
Has anybody done this successfully?
If we are using instance level replication:
Is there a way we can stop/start/modify replication for our application without affecting others?
Do setting differ greatly? That is, is it realistic to share instance level replication settings across applications?
Non-instance replication just looks hard, do I have the wrong view here?
Our customers use SQL Server 2008 R2 or SQL Server 2012.
At an instance level, replication configures only one distributor. That is, regardless of how many databases you have configured for replication on an instance, they'll all share one distributor. You do have the option to make that distributor local (i.e. on the same instance) or remote. So, if you find that distribution is taking up considerable resources (or anticipate that that's going to be the case), configure remote distribution.
Whatever drive holds your databases' log files will need to have sufficient headroom in their throughput to handle the logreader agent. If you're concerned that your database's activity will be impacting to other databases, isolate.
As for other concerns, replication is a lot like your line of business application. That is, it needs to read data (from the publisher and distributor depending on which phase of replication you're talking about) and write data (from the distributor and subscriber again depending on which phase of replication you're talking about). Provision resources accordingly and you should be just fine.
Recently my clients have asked me if they can use they’re application remotely, disconnected from the local network and the company server.
One solution is to place the database in the cloud, but a connection to the database, and the cloud and an internet connection must be always available.
There not always the case.
So my question is - Is there any database sync system, or a synchronization library so that I can work disconnected with local database and when I connect synchronize the changes I have made and receive changes others have made?
Update:
The application is under Windows (7/xp) ( for now )
It's in Delphi 2007 win32
All client need to have Read/Write access
All Clients have internet connection, but not always ON
Security is not critical, but the Sync service should encrypt the communication
When in the presence of the companies network the system should sync and use the Server Database and not the local one.
You have a host of issues with thinking about such a solution. First, there are lots of possible solutions, such as:
Using database replication within a database, to mimic every update (like a "hot" backup)
Building an application to copy the database periodically (every night)
Using a third-party tool (which is what you are asking, I think)
With replication services, the connection does not have to always be up. Changes to the database are logged when the connection is not available and then applied when they can be sent.
However, there are lots of other issues when you leave a corporate network. What about security of the data and access rights? Do you have other options, such as making it easier to access the database from within the network? Do the users need only read-access to the database or read-write access? Would both versions need to be accessed at the same time. Would there be updates to both at the same time?
You may have other options that are more secure than just moving a database to the cloud.
I believe RemObjects DataAbstract allows offline mode and synchronization by using what they call Briefcases. All your other requirements (security, encrypted connections, etc.) are also covered.
This is not a drop-in replacement, thought, and may need extensive rewrite/refactoring of your application. There are lots of upsides, thought; business rules can/should be enforced on the server (real security), scriptable business rules, multiplatform architecture, etc.
There are some products available in the Java world (SymmetricDS lgpl license) - apart from actually being a working system it is documents how it achieved synchronization. Connects to any db with jdbc support. . There is a pro version but the user guide (downloadable pdf) gives you the db schema plus rules on push pull syncing. Useful if you want to build your own.
Btw there is a data replication so tag that would help.
One possibility that is free is the Microsoft Sync Framework: http://msdn.microsoft.com/en-us/sync/bb736753.aspx
It may be possible for you to use it, but you would need to provid some more detail about your application and operating environment to be sure.
IS it possible to share a database like .mdb and work fine? i try but sometimes the file where the databse is changes from DB to DB1 i use delphi Xe4 and Google Drive .
Thank´s