Okay so I have to sync data between two SQL Server Express instances and after a research I stopped at Sync Framework which I think can do the job.. but since I am pushed by time and I don't have much time to do a complete research I need to ask few questions before continuing..
Basically I will have a server database which will be cleaned once every two months and I need to have a mirror database that will contain all the records.
Does sync synchronize the records only in the destination table or it also changes the server table if there is deleted records in it?
Can I sync two SQL Server Express instances? Because I am reading the documentation and it only has SQL Server and SQL Server Express sync documentation..
Do I need to create the mirror table or sync will create it for me?
Thanks in advance :)
You can specify the sync direction, upload, download, upload and download, download and upload, its all up to you.
Yes, you can, the same SqlSyncProvider will work with SQL Express, SQL Server, Local DB and Azure SQL Database
When you provision, you will have to define the tables that needs to be sync (table, columns, etc...). you will then provision the sync, when you provision, if the tables dont exist, it will create it for you.
Sync framework is designed to work to synchronize databases, that means two way, and it includes some concept of conflict resolution. One way synchronization is called Mirroring.
No you can't. Sync Framework is an enterprise level solution. You
need to pay for it. With a SQL Server licence. Don't bother looking
elsewhere, a SQL Server license is actually pretty cheap compared to
the alternatives.
Do not know the answer.
Related
I was wondering which one is the best way to replicate some data of a database to another.
I have a database in one computer and this one receives some transactions. I need to send this data to another server (in the same local network) but with a modified value (I need to add 11 years to a Timestamp value).
So I was looking for some options for my case, I can develop a windows service to do this but I don't know if the sql server replication can do this for me or if there is another option like some kind of magical trigger that can do that.
I'm using SQL Server 2005 on Windows Server 2003 R2.
This link should help you:
Selecting the Appropriate Type of Replication
Quoted summary from link:
Microsoft SQL Server offers three types of replication. Each type of
replication is suited to different application requirements. Depending
on the needs of your application, you can use one or more types of
replication in a topology:
Snapshot replication
Transactional replication
Merge replication
I personally would replicate the database (transactional) and then use log shipping to update the replicated database (on your second server) with the latest data changes (from the primary server) then use a stored procedure running as a sql agent job to update the fields you need.
I personally am not a fan of triggers as you can end up having triggers activating other triggers and something that takes milliseconds to run can take seconds and if you have large volumes of data that can be painful (I manage a system that has exactly this issue - soon to be replaced thankfully)
hope this helps and if you have some follow up questions I'll be happy to help.
Right now I am having a customer who is working with several businesses. He is working with their data but is not allowed to directly access their databases. We thought of using SQLite or SQL CE and storing a copy/part of the original database as a file on a network share. Now the problem is that SQL CE is not supporting it and SQLite highly recommends not to do so.
First of all the performance is a huge problem, since our customer is working with a lot of data (up to several gb). The second problem is that SQLite has problems (actually the underlying os functionality for file locking is the problem) with concurrent usage of the database, when it is stored on a network share. I did a lot of research on that topic and many people say that it is just a matter of time that the database gets currupt.
Does anyone know a better solution to that problem or a workaroung which lets me use SQLite? It does not need to be a file based database, as long as nothing needs to be installed or run on the server.
Thanks, David.
If you are going to store data on a network share and have concurrent users accessing it you are going to need a db that can handle concurrent access. MS Access will quickly die if under concurrent access as will SQL Lite.
SQL Server Express is free and works very well. PostgreSQL as suggested by Maxim is an open source full featured db that will do the job very well but may be overkill.
You could also look at Redis ... fast lightweight in memory no sql db that also has capability to persist to file.
You can try PostgreSQL. It is very easy to configure, and is rather reliable. It also support server export/import options.
And any of this makes sense, if you client is able to get his hands on an exported database somehow.
I need to update existing data or insert new data from client database say DB1 into central database say DB2 both holding same schema and both databases reside in same machine. The updates are not biderectional. I just want changes to be reflected from client(DB1) to server(DB2).
The client database(DB1) is nothing but the backup database(Full database backup consisting of mdf and ldf files) which is attached to the same server where the central database(DB2) exists. I am not going to make any changes to the backup database(DB1) once it is attached to the server. The backup database(DB1) already has the modified data which i want to update it to central database(DB2) . So how do i do programatically using C# .NET?.Can you give any example code?
I have tried transactional replication with push subscription without sending the snapshot. The problem is that the i want to update the modified data from DB1 to central database DB2 at the first shot itself but transactional replication will not allow me to do so. It will not send any modified data which is already present in DB1. So the initial data present in DB1 is untouched when you try to send without snapshot. The backup database (DB1) already has the modified data prior to replication. How do i tackle this as i am not going to insert any new or modify data into the backup database(DB1) after i set replication.
Thanks and regards,
Pavan
Microsoft Sync framework is the best solution, especially if you are using express editions (in which case replication will not work).
Sync framework is quite straight-forward if used with SQL server change tracking in sql server 2008. You can define your mode of synchronization as well (bi-directional, upload only, download only) and also define what happens when there are conflicts (for instance constraints get violated, etc).
And yeah - just google for an example there are several straight forward walk throughs available on the topic, including peer-peer synchronization (might be the one you require) and client-server synchronization (client should be sql server compact edition).
You may also want to explore SQL Server's merge replication functionality. It is the replication type designed to allow satellite databases to automatically post back their results to a central repository.
To achieve this you have the following options:
1.) Use SQL Server Transactional Replication. Make DB1 as Publisher, DB2 as Subscriber and go for Pull or Push based subscription. All changes in DB1 will be simply reflected to central. If any changes we there in Central for the same tuple, they will be overwritten by DB1 changes.
Advantages: Easy to implement and reliable
Disadvantages: Very little customization
2.) Use Microsoft Sync Framework SQLDataBaseProvider.
Advantages: Very Flexible
Disadvantages: I have heard bad things about it but never tried.
3.) Custom Implementation: This is a bit hard as you need to track changes on DB1. One option can be reading transactional logs which Transactional Replication does internally or other option is to use trigger and build knowledge of changes. Then you need to write a library or routine which will get you change knowledge then it will apply to central.
Edit:
For backup and restore database progmatically:
http://www.mssqltips.com/tip.asp?tip=1849
I need to copy several tables from one DB to another in SQL Server 2000, using C# (VS 2005). The call needs to be parameterized - I need to be able to pass in the name of the database to which I am going to be copying these tables.
I could use DTS with parameters, but I can't find any sample code that does this from C#.
Alternatively, I could just use
drop table TableName
select * into TableName from SourceDB..TableName
and then reconstruct the indexes etc - but that is really kludgy.
Any other ideas?
Thanks!
For SQL Server 7.0 and 2000, we have SQLDMO for this. For SQL Server 2005 there is SMO. This allows you do to pretty much everything related to administering the database, scripting objects, enumerating databases, and much more. This is better, IMO, than trying a "roll your own" approach.
SQL 2000:
Developing SQL-DMO Applications
Transfer Object
SQL 2005:
Here is the SMO main page:
Microsoft SQL Server Management Objects (SMO)
Here is the Transfer functionality:
Transferring Data
How to: Transfer Schema and Data from One Database to Another in Visual Basic .NET
If the destination table is being dropped every time then why not do SELECT INTO? Doesn't seem like a kludge at all.
If it works just fine and ticks all the requirements boxes why create a days worth of work growing code to do exactly the same thing?
Let SQL do all the heavy lifting for you.
You could put the scripts (copy db) found here
http://www.codeproject.com/KB/database/CreateDatabaseScript.aspx
Into an application. Just replace the destination. To actually move the entite database, FOLLOW
http://support.microsoft.com/kb/314546
But remember, the database has to be taken offline first.
Thanks
I have been asked to setup a course leaflet system for a college. For whatever reason in the past their current system is not linked to their actual course file, they wish to close this link so course leaflets are related to actual course codes. Unfortunately their course file is a ms access database linked to many of their existing systems (cannot easily be upgraded/moved). Since the course leaflets are going on the web it is a requirement with their hosting to use a sql server database.
This means I need to query between the two internally so they can work out what courses they have without a leaflet, I would not like to add ad hoc queries to the access database to do this.
What is the best way to do this in C#, I think LINQ can do it but have not learnt it yet, should I learn it for this project or is there an easier way?
I thought about a linked server to the ms access db but this would require moving the db to the sql server. Another difficult task as from what I can tell links to the database are hard coded.
Just how often does the course file change? Fifty times a day? Once a month?
What about creating the appropriate tables in the SQL Server database? Then every so often (as often as necessary to stay reasonably current), clear those tables out and repopulate them from the Access database. You could set this to run every morning at 3 a.m. or whatever. Or you could just do it periodically whenever the tables change significantly.
Why do you need the Access file to the SQL server to create a Linked Server? Just put it on a network share with appropriate security and create your linked server like that.
To add, LINQ has nothing to do with SQL or Access or anything else, it's for querying in memory object collections. Some linq providers allow you to use that to access your DB in question, but they won't be much help in this situation, I think.