I have deployed same application in two different computers. Now i need to merge both data from two different database into single database.
The application is developed using c# .net and uses sql express 2008.
The problem arised because i could not use the application over LAN.
So i need to merge the two database into one.
So please help me to solve the problem to merge it.
I also need to run the application over LAN but the sqlbrowser doesnot start and i have searched the internet for the answer but i haven't been lucky.
thank you, waiting for response.
The approach you want to take will depend largely on your schema, but Microsoft Sync Framework should likely be useful. It would let you define rules for resolving conflicts and merging your data.
As for accessing your data over the LAN, this post has a good overview of what it takes to enable remote access to your SQL Server Express.
Related
I have a problem concerning legacy application that can’t be changed in any way (single executable file with no dlls) which is connected to a database that can be changed. It is a visual basic 6 application connecting to the database using ADO.Net. Database engine is a SQL Server 2008. The goal is to create new correct database that will work with legacy application
It is coupled so tightly, that it does not even work with views instead of tables as suggested here. So the present situation look like this: current situation diagram
Currently I am trying to research into the problem and find my options. I have some idea that might work:
Since the approach to change tables to views does not work, I think that one possibility is to intercept the communication between app and legacy DB, read a sent command and redirect it somewhere else and not letting legacy db respond to the request.
Each command is either CRUD or procedure execution and we know what possible commands can be sent. Let’s suppose that a new database is set and has views corresponding to the legacy one. Commands are redirected to my own application that filters out everything and manipulates it (somehow) to work with the new schema.
Diagram of intercepted communication
This is my general idea of what I want to do to avoid rewriting the legacy application which is tightly coupled. Someone already asked a question similar to mine.
They discuss approach how to either dig commands from sql dump files or to intercept the communication.
The interception itself doesn’t seem to be a problem as discussed here. But I wonder how can the mirror reply.
The same goes for port mirroring using [TCP packet hijacking] (https://reverseengineering.stackexchange.com/a/1816)
To sum up, my questions are as follows:
Is that feasible approach to achieve smooth transition from a legacy modifiable solution to new one?
If my idea is doable, how can I listen to db requests and create responses from a different application and not the original db?
Is there a better way how to achieve my goal which is to create new database with database abstraction layer so the old legacy application will remain functional?
I need to connect Salesforce to an external database we have, and constantly keep both the database and salesforce updated in as close to real time as we can get. I have tired Google searching possible solutions, but nearly all of them have been outdated by over a year. Any ideas?
Thank You!
Depending on your exact scenario it is quite difficult to give you a proper answer.
However off the top of my head I would suggest two Salesforce products.
Salesforce Connect
https://www.salesforce.com/products/platform/products/salesforce-connect/
Salesforce Connect allows you to connect to various data sources and turn the tables / objects of that data source into a SObject. For example MySQL, Microsoft SQL Server, Oracle etc. There are limitations and thus it would be better to talk to a Certified Architect about such an implementation.
Heroku Connect
https://www.heroku.com/connect
Heroku Connect allows you to connect a Heroku data source with a Salesforce Object. The sync is not immediate but there are quite a few customisations inside the product to make the sync as "live" as possible. There are limitations and thus it would be better to talk to a Certified Architect about such an implementation.
Salesforce Connect has limitations.. It's good for presenting data via the interface, but if you need to act on the data and report on the data it might not be the best bet.
For close to real time hand coded sync, look at the streaming API, or using Salesforce Platform Events.
If you want to use an ETL tool, my organization has had decent luck with DBAmp, which is a Sql add on product and fairly inexpensive as compared to a lot of ETL tools ($1625 annually.) http://www.forceamp.com/ We're able to replicate the entire SF database offline in SQL with DBAMP, push changes to the offline Sql copy and upsert changes. It's also a good backup solution via offline full data copy. We got very good support from them as well when we encountered challenges.
Hope this helps.
Not sure if you are syncing one object or multiple objects but there are a few options that you have.
You can try the salesforce provided features Salesforce Connect which allows you to view and update data from your external source In salesforce but there are limitations with reporting and other considerations you should consider.
If you make use of Heroku, Heroku Connect is your best bet
You can also use a middleware ESB solutions like MuleSoft which can orchestrate keeping data in sync across multiple data sources and do batch loads, but depending on how often changes you want to keep an eye out for api limits for inbound calls to salesforce.
You can roll your own solution where you can use Outbound Messages in workflow (or triggers that initiates an apex class that calls out, but that is more cumbersome and you have to do custom error handling and retry logic which you get for free using outbound messages) to send changes from salesforce to your homegrown service that writes to you database and have you homegrown solution write back to salesforce using the soap or rest api. That would probably take you some time to build. You would also still need to be aware of API limits depending on how many updates are made on the non salesforce side.
You crate a Canvas App which displays data from your DB in Salesforce as a Tab and hook it up via SSO so users are auto logged in. But again there would not be reporting, or any salesforce features that you can take advantage of.
But I really think that you should spend some time to determine what system is your source of truth because that would determine how the data should be synced. You should also investigate if you really need the sync to be realtime or near realtime, or if you can manage with something like an hourly true up on the system that is not the source of truth.
My small team used asp.mvc 2.0/entity framework 4.0(model first approach)/Windows Server 2008r2/Sql Server 2008 r2 stack in out web site project. We've already complete developing process, and come to the web deployment stage. In this stage we are faced with the problem - ok we'll use vs2010 features for initial server/db deploy, but what we'll do in the future? Obviously some of our models can be modified after publishing in order to satisfy new conditions, and of course our server db will contains users data sets, articles etc. Is there any approach to update servers db with new db modification, without dropping db, and converting data from old instance to the new one?
Now we have found only DAC/DACPAC approach to update server db, but we don't know how to bind auto EF model generation with DAC.
May be there is exists another solution? Is there any standard way to resolve this kind of situation? Any advice?
Thanks
I'd be interested to know if you have found a solution to this yet?
Have you tried simply generating a database based on your EF model, and using a schema comparison tool such as SQL Compare to deploy changes from the EF-generated database and your target production server?
Let me start by saying: this is my 1st post here, this is a bit lenghty, and I havent done Windows Forms development in years....with that in mind please excuse me if this isn't directly a programming question and please bear with me as I really need the help!!
I have been asked to develop a Windows Forms app for our company that talks to a central (local area network) Linux Server hosting a PostgreSQL database. The app is to allow users to authenticate themselves into the system and thereafter conduct the usual transactions with the PG database. Ordinarily, I would propose writing a webforms app against Mono, but the clients need to utilise local resources such as USB peripheral devices, so that is out of the question. While it might not seem clear, my questions are italised below:
Dilemma #1:
The application is meant to be always connected. How should I structure my DAL/BLL - Should this reside on the server or with the client?
Dilemma #2:
I have been reading up on Client Application Services (CAS), and it seems like a great fit for authentication, as everything is exposed via URIs. I know that a .NET Data Provider exists for PostgreSQL, but not too sure if CAS will all work on a Linux (Debian) server? Believe me, I would get my hands dirty and try myself, but I need to come up with a logical design first before resources are allocated to me for "trial purposes"!
Dilemma #3:
If the DAL/BLL is to reside on the server, is there any way I can create data services, and expose only these services to authenticated clients. There is a (security) requirement whereby a connection string with username and password to the database cannot be present on any client machines...even if security on the database side is quite rigid. I'm guessing that the only way for this to work would be to create the various CRUD data service methods that are exposed by an ASP.NET app, and have the WindowsForms make a request for data or persist data to the ASP.NET app (thru a URI) and have that return a resultset or value. Would I be correct in assuming this? Should I be looking into WCF Data Services? and will WCF work with a non-SQL Server database?
Thank you for taking the time out to read this, but know that I am desperately seeking any advice on this! THANKS A MILLION!!!!
EDIT:
I am considering also using NHibernate as my ORM
Some parts of your questions are complicated and beyond my expertise. However, in general you can do almost anything you put effort into, CAP theorem and the like aside.
DAL/BLL stuff in general can reside in any of the tiers. I put a lot of this in my database and some in the middle tier, however this is to allow re-use in different environments which may or may not be a goal for you. The thing is I would think through carefully the separation of concerns issues here and what sorts of centralization of logic you want to place. The further back, the more re-usable this becomes but this is not always a free tradeoff.
I am not entirely familiar with CAS but it looked like AJAX kinds of stuff from what I saw on the MSDN web site. That could be wrong, but if it is right, then you have an issue in that such requests may be stateless and this could be an issue if you need a constant connection.
On the whole based on what you are saying it sounds cleanest to do a two tier rather than a three tier app, and have the DAL/BLL sit on the client, possibly supported by stored procedures in the server. You can then set PostgreSQL up to authenticate against whatever you use on your network (KRB5 if AD is what I would recommend). This simplifies your data access, and it allows you to control permissions based on the authentication against the database. Since you can authenticate users based on AD, you can then set permissions accordingly.
One important consideration is going to be number of connections. PostgreSQL does have some places where every current connection must be checked and iterated through, and connection startup and tear-down overhead in some cases can be significant. So one important decision will involve connection pooling. Whether or not you use connection pooling to boost performance will depend on what you are doing but I have seen cases where PostgreSQL has handled 600 connections without serious problems.
I'm looking for advices and suggestions on how to synchronise data between two databases.
The first database is a SQL Server 2008 Express that run on disconnected laptops (no network or internet access). The second database (main) is a VFP 9.0 that run on a server.
When the user connect their laptop on the network, I want the synchronisation process to go through.
Other than the different database engines, I have the following items to take into account:
The tables don't necessary have the same structure
The primary keys are not the same (GUID in the SQL Server and often a combination of character fields in VFP)
Synchronisation of the tables must be done in a certain order to respect the parent-child relationships
On some insert on the SQL Server side, a new primary key must be generated and synchronised in the VFP table
A bunch of validations must be made and some feedback from the user are sometimes needed
Not all records need to be synchronised
Some records on the SQL Server need to be deleted after the syncronisation
Need to take into account deleted records from both side
Minimal modifications need to be done on the VFP database
There are probably other points I'm forgotting now, but I think you get the idea of the challenge I face. My guess right now are that I will need to build a custom synchronisation module, but I want your input before I go on in case I overlooked some options and to get some tips on how to approach this.
I looked rapidly at Microsoft Sync Framework, but with all the restrictions I have and the fact that there is no VFP client already built (AFAIK), I don't think it will be of great help.
Thanks in advance for your feedback.
Update: The laptop application is a C# WinForm application and is using SQL Server 2008 Express.
The complexity of the situation and requirements leads me to believe you need to write a Visual FoxPro application. Visual FoxPro connects to SQL Server 2008 data easily. The complexity of the code is matching the requirements and identifying the data that needs to be synched, not the syntax. Visual FoxPro strength is in the data manipulation language and the ability to connect to almost any data source (native DBFs, ODBC, ADO, and XML).
SQL Server can read VFP 9 data via the VFP 9 OLE DB driver. You could write T-SQL stored procedures to get to the VFP data. Not sure how it would recognize the laptop being connected to the network though.
Another approach is to use SQL Server XML Diffgrams. I am not an expert by any stretch of the imagination on this approach, but it would be something you can research.
Since my expertise is with Visual FoxPro I would find it way easier to go the other way though, but that is just me. You have to go with the skillset of the resources you have for the project.
VFP reads and writes SQL Server data via a connection (DSN, ConnectionString) and any technique involving SQL Passthrough (SQLConnect(), SQLExec() and SQLDisconnect()), CursorAdapters, Remote Views, or a combination of the three.
A Visual FoxPro program can also recognize Windows Events like connecting to a network. The application could be installed on each laptop and running to recognize the Windows Event. Once the event is raised the application can attempt to connect to the SQL Server database (possible it is connecting to a network without the SQL Server available or a different network).
Once connected it runs the logic to check and synchronize the databases.
Sounds like you don't have a lot of control over the application writing to the VFP 9 data on the laptop. If you do have control over the application writing to the VFP 9 database you might consider changing the app to write to a SQL Server Express instance on the laptop and then you can use SQL Server replication to manage the synchronization. Not a trivial task though and SQL Server replication, while getting better with each release, does cause hair loss in DBAs. Definitely a lot of work going this route.
Rick Schummer
Visual FoxPro MVP
I would encourage you to take another look at MS sync framework. We have a situation where we want to synchronize occasionally connected C# clients apps with our Java/Oracle backend. You can use the sync framework providers for the C# client and implement your own custom subclass of KnowledgeSyncProvider for the backend. This will get you half-way there, and show you a good pattern to apply for the rest.