I'm working on an application and am trying to offer the ability to use a "Local" database or a SQL Server database. What I'm trying to work out is the best Local DB format to use and how to write the queries.
At the moment i have been playing with SQL Server CE and it seems to work fine, but I then need to write each code block twice for any queries (once for SQL and once for SQL Server CE). Is there any solutions to this? Is there some way i can just pass a different connection string?
What i have at the moment is a "sub" that i have a check if using local (my.setting.uselocal) and then call either function Query_SQL or Query SQL. I imagine it will get tiring soon to have to have two blocks for each database query?
Any suggestions on how to do this more efficiently?
Cheers
You could try creating a .sdf file. These can be created programmatically, along with a databse(s)/tables etc in the file.
It's been a long time since I've used them but IIRC you can write read/write with the same tsql syntax. I would have thought it would allow you the same query functions and you can then pass in whatever connection.
Related
This might be a bit of a stretch. I have an MS Access front-end that sits on our SQL Server back-end and uses a mix of VBA and SQL stored procedures to process data.
Several of my VBA procedures dynamically craft a SQL query by stitching together strings and then sending them over to the server to be executed. My question is whether this process can work in the reverse? For example, I set up a method in VBA that pulls a string from a table in the server and then executes it.
To clarify, I know how to use stored procedures to handle logic in the back-end. My goal here is to find a way to pull raw VBA out of a SQL table/store procedure and then run it in Access.
Yes, but I highly recommend you don't.
You can evaluate simple, single expressions using the Eval function in VBA.
You can import and modify modules through Application.VBE.ActiveVBProject.VBComponents. Here, you can modify the string contents of a module, but this requires exclusive access and recompiling the database while the code is running (thus I highly recommend you don't do this).
Generally, if you don't need to work with the Access application object, I recommend dynamically creating vbscript files instead, to avoid needing exclusive access and needing to recompile your database.
I have an access database that is stored on a network drive where all users access the one file. The database is linked to Sql server tables located in a local on site server. In my vba code my connection is to the access database. My question is I know it's possible to just connect to sql server from vba but all my queries are stored in Access, so will my code be able to run the queries from access if it's connected to Sql server or would I need to re-write all the queries? The problem we are having is that more than one user may be on the same record pulled up and they are overwriting each other's changes. Also a user may need to take the program on their laptop instead of having to remote in to their desktop at office. I was thinking I could just give them a copy each and that would solve the problem. Does anyone have any answers?
Just re-write the queries in SQL Server. It may be painful now, but it shouldn't be too bad, and down the road a bit, you'll be glad you moved everything to SQL Server (much faster, more stable, you're using a real DB, etc.)
You will want to pull all the queries into VBA and rewrite them with the appropriate parameters.
I have a vb.net project that uses a SQLite database. I do this by using dataset/table adapters. The client is happy and all works well. However I have just heard that they plan on providing this product to another customer that wishes to use their SQL Server database. So I am writing this post so I can mentally prepare for this before I begin. I am not a database pro and have really enjoyed the simplicity of setting up and managing an SQLite database.
So any ideas on the easiest way to support SQL Server as well? I am happy to run them parallel to each other. Can I just make a separate service / middleware that syncs the SQLite database to the SQL Server on a timer and does not care about what the main app is up to?
Any pointers are appreciated.
Synchronizing two databases is possible, if rather complex. You need some mechanism to find out which records have changed, and if it is possible to have new changes in both databases, you also have to resolve conflicts.
A timer-based approach doesn't sound efficient: in most cases, the timer doesn't have anything to do; and after some data change, there is some amount time where the databases are not synchronized.
Can't you just replace SQLite with MS SQL Server?
I.e., have some configuration settings that determines whether your program's data lies in SQLite or on a server?
Assuming that an SQL Server database with the required structure already exist, this would, in theory, need nothing more than a changed connection string, and supplying some user name/password (if the server isn't configured to automatically use Windows logins).
There shouldn't be any big differences in the SQL dialects used. You have, of course, to test all your queries.
Is there seriously no way of using a shared access non-server driven database file format without having to use an SQL Server? The Entity Framework is great, and it's not until I've completely finished designing my database model, getting SQL Server Compact Edition 4.0 to work with Visual Studio that I find out that it basically cannot be run off a network drive and be used by multiple users. I appreciate I should have done some research!
The only other way as far as I can tell is to have to set up an SQL server, something which I doubt I would be able to do. I'm searching for possible ways to use it with Access databases (which can be shared on a network drive) but this seems either difficult or impossible.
Would I have to go back to typed DataSets or even manually coding the SQL code?
Another alternative is to try using SQL
Install SQL Server express. Access is not supported by EF at all and my experience with file based databases (Access, SQL Server CE) is mostly:
If you need some very small mostly readonly data to persist in database you can use them (good for code tables but in the same time such data can be simply stored in XML).
If you expect some concurrent traffic and often writing into DB + larger data sets their performance and usability drops quickly. They are mostly useful for local storage for single user.
I'm not sure how this relates for example to SQLite. To generate database from model for SQLite you need special T4 template (using correct SQL syntax).
Have you tried SQLite? It has a SQL provider, and as far as I know EF supports any provider. Since it's file-based, that might be a plausible solution. It's also free.
This should be simple. I'm trying to import data from Access into SQL Server. I don't have direct access to the SQL Server database - it's on GoDaddy and they only allow web access. So I can't use the Management Studio tools, or other third-party Access upsizing programs that require remote access to the database.
I wrote a query on the Access database and I'm trying to loop through and insert each record into the corresponding SQL Server table. But it keeps erroring out. I'm fairly certain it's because of the HTML and God knows what other weird characters are in one of the Access text fields. I tried using CFQUERYPARAM but that doesn't seem to help either.
Any ideas would be helpful. Thanks.
Try using the GoDaddy SQL backup/restore tool to get a local copy of the database. At that point, use the SQL Server DTS tool to import the data. It's an easy to use, drag-and-drop graphical interface.
What error(s) get(s) thrown? What odd characters are you using? Are you referring to HTML markup, or extended (eg UTF-8) characters?
If possible, turn on Robust Error Reporting.
If the problem is the page timing out, you can either increase the timeout using the Admin, using the cfsetting tag, or rewrite your script to run a certain number of lines, and then forward to itself at the next start point.
You should be able to execute saved DTS packages in MS SQL Server from the application server's command line. Since this is the case, you can use <cfexecute> to issue a request to DTSRUNNUI.EXE. (See example) This is of course assuming you are on a server where the command is available.
It's never advisable to loop through records when a SQL Update can be used.
It's not clear from your question what database interface layer you are using, but it is possible with the right interfaces to insert data from a source outside a database if the interface being used supports both types of databases. This can be done in the FROM clause of your SQL statement by specifying not just the table name, but the connect string for the database. Assuming that your web host has ODBC drivers for Jet data (you're not actually using Access, which is the app development part -- you're only using the Jet database engine), the connect string should be sufficient.
EDIT: If you use the Jet database engine to do this, you should be able to specify the source table something like this (where tblSQLServer is a table in your Jet MDB that is linked via ODBC to your SQL Server):
INSERT INTO tblSQLServer (ID, OtherField )
SELECT ID, OtherField
FROM [c:\MyDBs\Access.mdb].tblSQLServer
The key point is that you are leveraging the Jet db engine here to do all the heavy lifting for you.