I have application that requires SQL Server 2000 as database storage.
I do not really want to use SQL Server 2000, but I can user MySQL Server instead.
Application uses ODBC to connect to SQL Server Database.
I would like to know if it is possible to make fake SQL Server which will send and receive data to/from MySQL Server
application <---> odbc manager <---> fake SQL Server driver <---> mysql server
Any one if such thing is possible to make?
If your application simply uses vanilla SQL via the ODBC driver, you should be able to use MySQL with few problems. If it uses specific features of SQLServer, then you need SQLServer - you cannot realistically fake it.
I wouldn't.
You're going to spend so long persuading the two to play nicely to no real benefit. You'll have to do most code the SQL Server way to work in this scenario. Given these, you might as well just bite the bullet and learn to use SQL Server directly rather than trying to tie the two together somehow, I'm afraid.
You can use a provider model and just switch out which provider your using at run time.
Of course, the biggest issue will be in the differing SQL code support. So you will have to take care that all of your SQL is located inside of each provider and stay away from any sort of embedding it in your application logic.. which you should be doing anyway.
Another way is to simply change the ODBC data source at deployment time, but again, you will have to make sure the SQL code actually works in both environments; which is tough.
Typically supporting multiple database back ends is a art form in itself. Simple things like SELECT TOP 100 for SQL Server 2k versus MySql's LIMIT command are enough to keep people from doing this.
There's no real way of "faking" it because the database servers are fundamentally different. You would end up writing a fair amount of code just to translate a sql call from one to the other... Which is a waste of time.
I'd suggest you just bite the bullet and learn MS SQL Server.
This site shows a very simple example of how SQL Server, Oracle, and MySql differ on just one implementation of a select statement.
Not sure why you "do not really want to use SQL Server 2000" but, if you decide you need to and you have a PC with Windows available, you can use the Microsoft Database Engine 2000 Release A (MSDE2000A.exe). It is the real thing and free to use on a desktop.
http://msdn.microsoft.com/en-us/library/ms811304.aspx
I do not think it is available for download from Microsoft anymore but you might be able to find it somewhere else. If you can't find it, your next best option may be to use the 2005 version (SQL Server 2005 Express Edition) and make sure you do not use any new features since 2000:
http://www.microsoft.com/Sqlserver/2005/en/us/express.aspx
Related
I'm working on writing a .NET console program, and one of the things that it is planned to do is CRUD operations on a specific set of data. I currently have that set up as a List, but I'm thinking a SQL database would be ideal. Problem is, I don't want the end user to have to install a SQL server for this program.
I looked at the question Include SQL Server database in application, which suggested using SQL Server Compact Edition. However, that is deprecated, and I would rather use something that isn't deprecated. MySQL is my SQL server of choice, but if that's not the best for this program, I am perfectly fine looking at other solutions.
Is it possible to have a SQL database as part of my program without requiring a SQL server for the end user? If so, how?
I understand that this is painfully generic and broad. Nonetheless, all the answers on wikipedia and yahoo (none here that I can find) are pretty useless.
I know T-SQL, C#, etc to some degree. I understand the idea of a database. However, I have NO idea what I created when I made a "server" on my computer through Msft SQL Server. Now I can make databases on that server, and I can connect to them with Visual Studio (sometimes) to use with LINQ or "raw" calls.
Please help me understand (or direct me to an article) of what this myComputerName\SQLEXPRESS (SQL Server xx.x.xxx) thing is. I assume the databases are stored locally...somewhere. SQL Server provides access to the DB files? Why can't they be accessed directly?
Thank you if you even read all this. I really can't narrow the question down.
I guess one specific question is "Can I access the databases without SQL Server running?" Where do I even get the connection string?
You are asking multiple questions, here.
However, I have NO idea what I created when I made a "server" on my
computer through Msft SQL Server. Now I can make databases on that
server, and I can connect to them with Visual Studio (sometimes) to
use with LINQ or "raw" calls.
Please help me understand (or direct me to an article) of what this
myComputerName\SQLEXPRESS (SQL Server xx.x.xxx) thing is.
The layout of a database server is as follows:
Server
Instance a
database aa
database ab
...
Instance b
database ba
database bb
...
...
So, when you install MS SQL Server, you install a MS SQL Server "instance". In this "instance", you can create a number databases. Each database has database files, the exact location of these depends on the settings you chose during installation.
I guess one specific question is "Can I access the databases without
SQL Server running?"
You do not usually open dbf(mdf -ldf) files (the database data files) without MS SQL Server, why would you want to ? You should use the backup/restore features inside MS SQL Server.
Where do I even get the connection string?
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring%28v=vs.110%29.aspx
The "server" is a process/service running on your computer which can be connected to over the network and provides the API to access your database.
"Why can't they be accessed directly?" Is like asking why do I need Word to view Word files, can't I use Notepad for that. Sure you can, but not really.
Another reason is - imagine multiple processes need to access the database. If each reads and writes to the same files, something WILL break if they don't coordinate. Having a separate server process encapsulates all this.
"Can I access the databases without SQL server running?" I mean yes but actually no.
If you want a database that your program accesses directly (or let's say, your program is also the database server in a sense) - then you can use sqlite, or for simple tasks there are also ODBC drivers for CSV, so you can use CSV files as if they were a database. A dedicated SQL server is always better for bigger more complex tasks and data models though.
I have a client who has a VB 6.0 application with MS Access as backend. But, now the Access is unable to take the load. So, we are now considering to shift to SqlExpress Edition. Also, we will convert VB6.0 application to c# based Winforms. My questions -
1) Can SqlserverExpress support 10 users concurrently? If not SqlExpress, then what other options are available?
2) Should I first convert VB 6.0 to C# application? Because, if I transfer data to Sqlserver, will VB 6.0 application continue to work?
thanks
Yes it can
You don't need to convert your app, but Access and Sql Express - are different database engines, so you will need to adopt your app to sql express
Note, that sql express prior to 2008 R2 can handle up to 4 Gb databases, while 2008 R2 can handle up to 10 Gb per database.
1) SQL Express allows over 32 thousand simultaneous users. The only real limit is database size, which is 10 Gigabytes.
2) You'll need to at least modify the VB 6 application to have the correct connection string before it will work with SQL server.
I am curious though why you say that Access (the JET database engine) is unable to take the load. Usually 20 or even more simultaneous users are no problem.
If product is for in house use and doesnt generate cash you can use oracle. Its free to use unless your app is for commercial use.
One question to ask is after how many users does the system slow down? And if it is slow with one user, then this might be some software design issue and not necessary the "load" on the server. There also the issue of the type of connection WAN or LAN. In fact you can read about this issue in the following article:
http://www.kallal.ca//Wan/Wans.html
The above in a nutshell explains why the Access data engine does not work well on a WAN.
Also migration of data to SQL server without determining what particular issue is causing the slowdown could very well result in a further slowdown. In other words often just up-sizing data to a server database engine will not solve performance issues and in some cases it can become worse.
In fact in many on line Access forums we often see users complain of a slowdown when moving the back end data file from Access to SQL server. So just moving to SQL server without taking advantages of SQL server features does not always guarantee a performance boost.
The other issue you want to determine here is if the VB6 program uses ADO or DAO. Either data object model is fine, but ADO would suggest LESS code will have to be modified then if the application is based on DAO.
Another issue is you not mentioned how large tables are, and the number. So say 30 to 50 highly related tables, and say a small number of rows (say 200,000) in some of the tables should run just fine with 5 to 15 users. If your user count is only about 10, and your table row counts are small as noted then performance should be ok, and if it is not, then as noted you might be able to keep the application as is and moving the data to SQL server may not yield performance gains without further code modifications. And of course SOME code will have to be modified to work with SQL server - how much will depend on the data object used, and how much code there is over all. (more recordset code = more chance of needing more code changes).
If you do decide to convert from Access to SQL Server Express, there is a migration wizard which can give you a quick start with that process. Here's the link
I've written my website using ASP.NET MVC and SQL Server (used a SQL Server instance which ran locally on my machine).
I'm about to upload my site to a hosting provider. However, his DB works under MySQL. I don't care about the data already in the DB itself. It's mostly mock data and a few tables which I don't mind rewriting. But how do I go about the transition from SQL Server to MySQL? How does this influence my queries inside my code? is it the same code syntax? Will I have to recreate the table definitions? In my project I used LINQ to SQL.
Am I forced to look for a host with SQL Server capabilities (i.e. licenses)? (I hope not...)
Thanks!
You may be able to transition smoothly, but I greatly doubt this will be the case.
The differences are many and whether you could depends on what features you used when developing.
If you kept to one of the standards, you may be in luck.
See a comparison sheet on wikipedia.
In regards to the Linq aspect of your question - you should be able to use a Linq provider for MySql instead of MSSql without a problem.
Here is a link to one: http://code2code.net/DB_Linq/
If you do decide to go with the MySql hosting, I suggest you test all aspects of you application to ensure they are working as expected.
LINQ to SQL works with MS SQL Server only...so if you want to keep using it, you need to find a host with a MSSQL database.
How do I select data from a MS SQL Server from MySQL? We have a system of linked server in SQL Server. I have also heard that you can do a linked server to Mysql from sql server. But I want to know the reverse.
The mssql server is what we use mainly for production. So one main reason we'd want to do this is simply to get the exact mssql server's time.
I dont think it will be possible, reverse is possible with only .Net scripting support. However, you may setup a time synchronization mechanism between two servers.