We are thinking of moving some of the 'hard coded' settings out of our windows forms application and storing them in the sql database in a table called App_Settings. The reason for this is we have values currently hard coded into appsettings and app.config which can change over time, and it is much easier and faster to update the values in a database table than it is to update, build and deploy the app over three servers.
Please can someone advise on this, and also how can we load the settings into the app and then have them readily available in any class?
Cheers
Richard
Have a look at this similar thread: Resources/App.config or Database where is the best place to application strings
When you want to store settings in the database i would implement the class as Singleton or at least as a Class with only static/shared members and a factory method(getAppSettings)which returns that single/static instance. So you could access your settings from everywhere and it is only initialized once.
Why don't you use something like YAML to save these settings? It would be easy to create a form to edit and save these settings in a file, instead of a db (which would add more maintainance problems).
Otherwise, I would suggest to use something like NHibernate to use a database, and SQLLite as the db server.
Also, note that if you are updating these settings, I would not say that these are App_Settings, since App_Settings aren't usually modifyable without
Help this helps,
Pietro
Related
So a friend of mine asked me to help him configure an automatic replication of a table on his MariaDB database to another table that's supposed to be an exact copy of the source/primary table.
The databases are on the same server. MariaDB version 10.2.44. The databases are on a cPanel managed webserver run by a webhost. We are accessing the databases using HeidiSQL, which is what I'm hoping I can use to configure everything.
Upon lots of googling, this is the article I suspect makes the most sense for what we want to do, but it doesn't look like this is automatic to any extent: https://mariadb.com/kb/en/setting-up-replication/
Is this the best way to do what we're trying to do? Is there a better way? Any suggestions?
Thanks!
Like #ysth said, in this case, triggers can be used.
When creating a trigger that "works between different databases", you need to specify the database on the trigger name. So for example:
CREATE TRIGGER database_name.trigger_name
Otherwise you'll get an "Out of schema" error.
The database you need to specify is the one where the "listener" is located. Basically, the place where the condition for the trigger is being checked.
I would like to customize ASP.NET Identity to work with an external database.
The default schema looks like that:
The part that bothers me, is the User table.
I succeeded to move the database to SQL Server Express and then I tried to modify the Table and deleted some columns.
When I tried to build and run the project I got multiple errors demanding for the columns I deleted and there is no mention to them in the code (Just new MVC project).
I would like that it will look more like this:
Of course I'll want to add some more table but that we'll be after the Users part will be complete.
So, is there some kind of tutorial that can explain how to customize Identity to my needs ?
Or anything help that can help me build stable users system.
I'm working with sqlite and qt. I understand that sqlite doesn't have native user access control and am fine with that, and have a plan for controlling access using my application - set up some user groups in a db and authenticate on the app side.
What I would like to know is if there is an easy way to stop my views on QSqlRelationalTableModel data from updating the database (i.e make the database readonly).
I am currently using an editstrategy of OnFieldChange, if I change it to OnManualSubmit for example (without implementing a submit call), will that prevent updates to the dB?
Is there a cleverer way of doing this? Like making the view readonly?
If you create views, then they will be read-only since sqlite doesn't support updating views:
http://www.sqlite.org/lang_createview.html
EDIT
Following-up on your comment, is the QSQLITE_OPEN_READONLY connection setting what you are looking for?
http://doc.trolltech.com/4.6/qsqldatabase.html#setConnectOptions
The scenario is this. I have a SQL Server database online that I am demoing an application. During development, I have added extra fields, modified field types, changed keys and added some new tables locally.
What's the best way for me to update the online database with the new structure and not lose the data? The database is a SQL Server 2005 one.
Download a trial of Red Gate SQL Compare, compare your two servers and you are done. If you do this often, it is well worth the $400, or get one of their bundles for a better bang for the buck.
And I do not work for Red Gate, just a happy customer!
Write update scripts to modify your live database structure to the new structure, as well as inserting any data which is required.
You may find it necessary to use temporary tables to do this.
It's probably best if you test this process on a test environment, before running the scripts on the live environment.
Depending on what exactly you've done you may be able to get away with alter statements, though from the sounds of it (removing keys and whatnot) you're doing some heavy lifting that may make that a less-than-ideal solution. You should probably look into creating a maintenance plan or, better yet, a SQL Server Integration Services project in Visual Studio. You should be able to migrate the data in the existing database to a new one using those tools.
This probably isn't of huge help retrospectively, but I always script all structural DB changes to my development database and then using a version number to determine the current version of the DB I can run the required scripts on the live DB, hence bringing it back in line at the same time as the new code is uploaded.
This also works for any content changes, for instance if the change in the underlying structure has an effect on the conent stored you can also write scripts to migrate the data accordingly.
Make a copy of the existing database to copy from.
Make another copy and alter it to your new schema. save DDL for reuse.
Write queries that copy data from #1 to #2. Save the queries for reuse.
Check the results.
Repeat until done.
I would like to find a way to create and populate a database during asp.net setup.
So, what I'm willing to do is:
Create the database during the setup
Populate the database with some initial data (country codes or something like that)
Create the appropriate connection string in the configuration file
I'm using .NET 3.5 and Visual Studio 2005, and the Database is SQL Server 2005.
Thanks in advance.
If you are creating an installer I'm sure there is a way to do it in there, but I am not all that familiar with that.
Otherwise, what you might do is the following.
Add a application_start handler in the Global.asax, check for valid connection string, if it doesn't exist, continue to step two.
Login to the server using a default connection string
Execute the needed scripts to create the database and objects needed.
Update the web.config with the connection information
The key here is determining what the "default" connection string is. Possibly a second configuration value.
Generally, you'll need to have SQL scripts to do this. I tend to do this anyway, as it makes maintaining and versioning the database much easier in the long run.
The core idea is, upon running the setup program, you'll have a custom action to execute this script. The user executing your setup will need permissions to:
Create a database
Create tables and other database-level objects in the newly-created database
Populate data
Your scripts will take care of all of that, though. You'll have a CREATE DATABASE command, the appropriate CREATE SCHEMA, CREATE TABLE, CREATE VIEW, etc. commands, and then after the schema is built, the appropriate INSERT statements to populate the data.
I normally break this into multiple scripts, but YMMV:
Create schema script
"Common scripts" (one for the equivalent of aspnet_regsql for web projects, one with the creation of the Enterprise Library logging tables and procs)
Create stored procedure script, if necessary (to be executed after the schema's created)
Populate initial data script
For future maintenance, I create upgrade scripts where a single script typically handles the entire upgrade process.
When writing the scripts, be sure to use the appropriate safety checks (IF EXISTS, etc) before creating objects. And I tend to make mine transactional, as well.
Good luck!
Well, actually I found a tutorial on MSDN: Walkthrough: Using a Custom Action to Create a Database at Installation
I'll use that and see how it goes, thanks for your help guys, I'll let you know how it goes.
If you can use Linq to Sql then this is easy.
Just import your entire database into the Linq to Sql designer. This will create objects that describe all objects in your database, including the System.Data.Linq.DataContext derived class that encapsulate the entire database setup.
Now you can call DataContext.CreateDatabase() to create the database.
See here more information.