I have a mobile db (SQL Server CE), which synchronizes with my database on a SQL-server via merge replication.
after some trobules with the device, I had to copy the mobile db from the device, but i couldn't sync anymore before that.
There are some important information in it and i have no other device to use the db there.
I can read it with SSMS, but i need it on the server and I don't want to copy it by hand (There are too many records in it, which changed and also a lot of new ones)
Is it possible to sync the SQLCE-Database without a device
Thank you
Related
I am developing an web application in which i need to maintain the website in the local servers itself with the database in the computer itself , the local database will change periodically.There is a central database through which i have to access all the data in all the remaining DB's .
The problem is that even when internet connection is disabled, the local server will update the local database but when when it regains the internet connection it has to update the central database with the local modified data.
The tables( i mean the database schema, table names, attributes all) in all the DB's is same.The data should be appended if added any new ,should be deleted if any deleted and should be modified if any.
I am using MySQL server as DB, Apache Tomcat as server and using JSP, Servlets for business logic.
Please visit http://dev.mysql.com/doc/refman/5.1/en/replication-howto.html
Mysql replication might do the job but there are a few things that you have to consider, like:
the amount of data that has to be synchronized
the OS used on master and slave servers
because of the internet connection issue - why you disable internet connection? one option might be a scheduled job (crontab)
I have two applications with own database.
1.) Desktop application which has vb.net winforms interface, runs in offline enterprise network and stores data in central database [SQL Server]
**All the data entry and other office operations are carried out and stored in central database
2.) Second application has been build on php. it has html pages and runs as website in online environment. It stores all data in mysql database.
**This application is accessed by registered members only and they are facilitied with different reports of the data processed by 1st application.
Now I have to synchronize data between online and offline database servers. I am planning for following:
1.) Write a small program to export all the data of SQL Server [offline server] to a file in CVS format.
2.) Login to admin Section of live server.
3.) Upload the exported cvs file to the server.
4.) Import the data from cvs file to mysql database.
Is the method i am planning good or it can be tunned to perform good. I would also appreciate for other nice ways for data synchronisation other than changing applications.. ie. network application to some other using mysql database
What you are asking for does not actually sound like bidirectional sync (or movement of data both ways from SQL Server to MySQL and from MySQL to SQL Server) which is a good thing as it really simplifies things for you. Although I suspect your method of using CSV's (which I would assume you would use something like BCP to do this) would work, one of the issues is that you are moving ALL of the data every time you run the process and you are basically overwriting the whole MySQL db everytime. This is obviously somewhat inefficient. Not to mention during that time the MySQL db would not be in a usable state.
One alternative (assuming you have SQL Server 2008 or higher) would be to look into using this technique along with Integrated Change Tracking or Integrated Change Capture. This is a capability within SQL Server that allows you to determine data that has changed since a certain point of time. What you could do is create a process that just extracts the changes since the last time you checked to a CSV file and then apply those to MySQL. If you do this, don't forget to also apply the deletes as well.
I don't think there's an off the shelf solution for what you want that you can use without customization - but the MS Sync framework (http://msdn.microsoft.com/en-us/sync/default) sounds close.
You will probably need to write a provider for MySQL to make it go - which may well be less work than writing the whole data synchronization logic from scratch. Voclare is right about the challenges you could face with writing your own synchronization mechanism...
Do look into SQL Server Integration Service as a good alternate.
A colleague I work with recently told me that SQL Express and MS Access were essentially the same thing; that does not seem to be an accurate statement. I know you can convert Access to a SQL DB and maybe under the covers they are similar, but I would assume that the SQL DB engine and what is used to run access are not the same. Not only that, but the SQL statement syntax, etc. I know are not the same.
I am mainly trying to understand so that I am more informed about the versions.
Um, no, not the same.
First off, I need to clear up some terminology. MS Access is a Rapid Application Development (RAD) tool that allows you to quickly build forms and reports that are bound to relational data. It comes with a file-based database engine (Jet/ACE).
Access the RAD tool can be used with many different backend databases (Jet, SQL Server, any db that supports ODBC, etc). I have to assume your colleague was specifically commenting on Jet/ACE, ie the database engine that MS Access uses.
I think the single biggest difference between the Jet/ACE database engine and MS SQL Server Express is that Jet/ACE is file-based and SQL Server Express uses a client/server model. This means that SQL Server Express requires a running service to provide access to the datastore. This can complicate deployment in some scenarios.
SQL Server Express is really just a throttled-back version of SQL Server: max database size of 4GB (10GB in 2008R2), only uses a single physical CPU, etc. These limitations are imposed to prevent large organizations from using the freely available Express edition in place of a full-blown SQL Server install. The upshot to this is that SQL Server Express offers a truly seamless upgrade path to SQL Server. It is also (generally speaking) a more robust and fully featured database management system then Jet/ACE.
Similarities
relational database management systems
written by Microsoft
Differences
MS Access
File based
free distributable runtime (2007 or later)
RAD tools (form/report designer)
uses Jet SQL
max file size 2GB
SQL Server Express
Client/Server model
free
no RAD tools
uses Transact-SQL
max database size 4GB (10GB for SSE R2), max one physical CPU
I think what your colleague had in mind was SQL Server CE, which is a super-lightweight embedded database, which is still (IMO) far superior to Access in database-management aspect. SQL Express cannot even be compared with Access without offending the former.
Here are the datasheets for both products so you can see some hard facts on the difference between the two databases.
Access:
http://office.microsoft.com/en-us/access-help/access-specifications-HP005186808.aspx
SQL (Express is listed on the far right column):
http://www.microsoft.com/sqlserver/2008/en/us/editions-compare.aspx
The comment I have always read is that Access is great for single user single access database use, the minute you scale beyond a single user look elsewhere. While that may be a "bit" of a stretch, Access really does not do well in a multi-user environment. From experience we've had a client who has ignored and ignored our requests to migrate a backend database from Access to SQL, and there have been numerous occasions where we have had to restore from backups, or take the Access database offline due to corruption.
They are two completely different technologies with two different target markets. The database engines are indeed different, as you mention T-SQL is different than Access SQL.
You can "scale up" an Access database to SQL by creating an SSIS package or other tool to do the import, but this takes the Access schema and data and migrates it to a true SQL database. It does more than just attach the Access database or the like.
Anytime you need a "real" database I'd highly recommend looking at any of the SQL versions that are available over Access.
Just remember that with MS-Access you don't have size limitations if you play your cards right. There is no reason, for example, not to have many 2 to 4 Gig tables each contained singularly in their own database. Your ODBC applications can open a connection to multiple MS-Access databases and query the single table in each. So you can have a database containing trillions of records, stored in multiple MDB files. One company I went to work for was using a single MS-Access database to run a issue tracking system done in MS-Access forms. They could only use it one person at a time because of sharing issues that would lock MS-Access up. I wrote a Win32 Perl native Windows GUI user-interface to the database that was better at field/record validation, and my ODBC code was able to manage the connection for simultaneous user access. I managed the opening and reading and writing and closing of the database for each user through my Perl program. I did not leave the database open. I did not maintain a persistent connection for each user, but instead only maintained a connection long enough to retrieve a record for edit. Then I closed the connection until it was time to write the record back to the database. Also, I wrote my own record locking program logic by maintaining a user login table that contained the record id of the record a user was currently editing, then erased that entry when no longer editing that record. When another user went to edit the same record, the program checked if that record was currently open for edit by another user. The system worked flawlessly. MS-Access never locked up via ODBC and multi-user access. I even embedded the password to the database in my compiled Perl program so that no one could get to the data in the Access database other than through my Perl program.
The current application I'm working lets call X is an archiving application for the data kept another application say Y. Both are very old applications developed about 8 odd years back. So far in my reading of the documentation, I have learnt that the process to transfer data used is that, the SQL Server Database Tables snapshot is created in flat files and then this flat files are ftp'd to the correct unix box where through ctl various insert statements are generated for the Oracle Database and that's how this data is transferred. It uses bcp utility. I wanted to know if there is a better and a faster way this could be accomplished. There should be a way to transfer data directly, I feel the whole process of taking it in files and then transfer and insert must be really slow and painstaking. Any insights???
Create a DB Link from your Oracle Database to SQL Server database, and you can transfer the data via selects / inserts.
Schedule the process using DBMS_SCHEDULER if this needs to be done on a periodic basis.
you can read data from a lot of different database vendors using heterogeneous services. To use this you create a service on the Unix box that uses - in this case - odbc to connect to the SQL Server database.
You define this service in the listener.ora and you create a tns alias that points to this service. The alias looks pretty normal, except for the extra line (hs = ok). In your database you make a database link that using this tns alias as connect string.
UnixODBC in combination with the FreeTDS driver works fine.
The exact details vary between releases, for 10g look for hs4odbc, 11g dg4odbc.
I have a client that uses a point-of-sale solution involving an Access database for its back-end storage. I am trying to provide this client with a service that involves, for SLA reasons, the need to copy parts of this Access database into tables in my own database server which runs SQL Server 2008. I need to do this on a periodic basis, probably about 5 times a day.
Is there an easy programmatic way to do this, or an available tool? I don't want to handcraft what I assume is a relatively common task.
I am running this on SQL Azure, so there's no way for me to run prepackaged software on the server. It would either have to be open source and portable to Azure or executable on the client's computer.
I'm unfortunately thinking I'm going to have to roll my own tool to do this. Any suggestions or more tools that are out there that can do this themselves before I go ahead?
David, I looked at multiple solution for a similar problem: converting from dbf to mysql, here are 3 solutions (all commercial - but relatively inexpensive) that can work for you:
Full Convert
SQL Manager
ESF
Other than that I couldn't find a good robust data conversion tool that would be open source or free. At least not for DBF to MySQL conversion. There might be something out there for SQL/Access. You could roll out your own solution, but is it worth your time?
DISCLOSURE: I ended up using Full Convert.
Also all of these products generate some sort of batch file, that can be scheduled using Task Manager.
There are two things to consider:
connectivity
ETL tool
For connectivity, you will need to establish VPN tunnel of some sort between the client server and your server.
Then use SSIS to connect to MS Access, to create packages to pull data from MS Access to SQL Server database. On SQL Server, you will need to create new schema, to mirror or be close MS Access
On connectivity side, another option - since MS Access db is in the file, you may be able to FTP the file to your server and point SSIS to the file