I am using ServiceStack to build my API/Service. Database communication is done through OrmLite which is supported by ServiceStack. Database connection is being used through IDbConnectionFactory.
My database (SQL Server) is being updated through SQL Replication (receiving data updates from another database). I want my cache (service level) to be cleared once a update is made to the database through any source.
Is there any way i could use SQLDependency or any other mechanism to always get the updated data along with using cache?
Normally, you would use something like ServiceBroker to get notifications for database changes.
Try checking out this other question, someone provides an answer with SQLDependency: How to monitor SQL Server table changes by using c#?
I'm new to ServiceStack myself so I'm unsure if they have within their framework something that would do this with minimal setup.
Related
I have a CouchDb instance running a peruser database configuration.
Each user database generated (when a user is added to the _users database) needs to have the same design documents with view/list logic etc.
What is the defacto way to add the design documents to the database upon database creation? Is it simply to add them after a successful user creation request? Or is there a more elegant way of doing this in CouchDb?
There is not a mechanism for initialize newly created user databases, you should include it in your user creation logic.
If you want to decouple user creation and db initialization, I suggest you to explore the following strategy
1 - Create a template database and place on it your design documents that should be applied to every user db
2 - Listen continuously _db_updates endpoint where db level events will be notified. This library can help you.
3 - When a db that matches the user db name pattern is created, you can trigger a replication from the template database to the newly created database using the _replicate endpoint.
If you plan on using the Follow npm module as #Juanjo Rodriguez suggested, please consider using the Cloudant's version. The Iriscouch's version (the one pointed by #Juanjo Rodriguez) is way out of date. For example it doesn't support CouchDB v2.x among other issues. I worked with the Cloudant's team to improve all this these last days and they just released the updated npm package yesterday here: https://www.npmjs.com/package/cloudant-follow?activeTab=versions
The 0.17.0-SNAPSHOT.47 version embarks the patches we worked on so don't use the 0.16.1 (which is officially the latest).
You can read more about the issues we fixed here:
https://github.com/cloudant-labs/cloudant-follow/issues/54
https://github.com/cloudant-labs/cloudant-follow/issues/50
https://github.com/cloudant-labs/cloudant-follow/issues/47
Here is my situation. I have an extensive REST based API that connects to a MongoDB database using Mongoose. The API is written as a standard "MEAN" stack application.
Currently, when a developer queries the API they're always connecting to the live production database. What I want to do is have an exact duplicate database as a "staging" database, where new data will be added first, vetted over a period of time, and then move to the live database. Then I want developers to be able to query either one simply by modifying their query.
I started looking into this with the Mongoose documentation, and it appears as though the models are tied to the DB connection, and if I want to have multiple connections I also have to have multiple models, one for each connection. This would be a nightmare of WET code and not the path I want to take.
What I want to do is not touch any of my code at all and simply have a switch that changes to the proper database for a given query. So my question is, how can I achieve this? Is it possible? The documentation seems to imply it is not.
Rather than trying to maintain connections two environments in the same code base have you considered setting up stage version of your application? Which database it connects to could be set through an environment variable or some other configuration option.
The developers would still then only have to make a change to query one or the other and you could migrate data from the stage database to production/live database once you have finished your vetting process.
We have Oracle 11 as database for our third party server application. The interactions for db is only allowed through the interops DLLs provided by vendor. No direct access to database is allowed. We need to connect to the database using those DLLs for creating or deleting objects inside the database. I am wondering if I can use Nhibernate by writing some wrappers about those DLLs. No SQL queries are also allowed. Can this be done?
Who is vendor? Not Oracle I guess, but your "third party" providing the "application server" software.
In such case this looks like they want to forbid direct SQL access to their application DB. So there is no point trying to use an ORM such as NHibernate, it would be from their point of view almost like directly querying the DB.
Your "best" option is to ask them if they can provide their own NHibernate database driver, but their answer will very probably be "No".
I'm attempting to make my existing SQL Server 2008 database compatible with the Windows Azure platform by using SSDT, however I am getting a whole bunch of errors when I build the project due to TVFs and views looking for an external database that sits in the same instance in SSMS.
I've added the database that its looking for into Azure, which wasn't a problem.
I've found that if I load the offending piece of code I can add the Azure server address to the FROM statement which resolves the error (shown below), however I have a huge number that rely on the external db and hoped there may be a quicker way?
FROM [myAzureserver.database.windows.net.ExternalDBName.dbo.TableName] as ALIAS
I understand that this issue would not exist if I merged the databases, however this isn't possible at present.
Thanks a lot for your help.
Why are you trying to make your local SQL Server Azure compliant? Are you planning to move it at some point in the cloud? If so, you won't be able to use linked servers. Your FROM clause will work as long as the database remains on an on-premise SQL Server instance.
Assuming that's what you want to do, you are asking if there is quicker way to change your references to point to the cloud database, right? I am not sure if this will work for you but I had a similar issue on another project and ended up using synonyms. Check our synonyms here: http://msdn.microsoft.com/en-us/library/ms177544.aspx. Although you can't create a synonym for a server, you can create synonyms for tables/views/procs.
Again, this may not work for you, but let's try this...
Assuming you have your primary database called DB1, the secondary database called DB2, and the cloud database of DB2 called AzureDB2, you could create synonyms in DB2 to point to the cloud database without changing any SQL statement from DB1.
So assume you have this statement today in DB1:
SELECT * FROM DB2.MyTable
You could create a synonym in DB2 called MyTable:
CREATE SYNONYM MyTable FOR [myAzureserver.database.windows.net.ExternalDBName.dbo.TableName]
DB2 becomes a bridge basically. You don't need to change any statement in DB1; just create synonyms in DB2 that point to the cloud database.
Hopefully this works for you. :)
I currently developed an app that connects to SQL Server 2005 database, so my DAL objects where generated using information from that DB.
It will also be possible to connect to an Oracle and MySQL db, all with the same table structures (aside from the normal differences in fields, such as varbinary(max) in SQL Server and BLOB in Oracle, and so on). For this purpose, I already defined multiple connection strings and multiple SubSonic providers for the different DB's the app will run on.
My question is, if I generated my objects using a SQL Server database, should the generated objects work transparently with the other DB's or do I need to generate a different DAL for each database engine I use? Should I be aware of any possible bugs I may encounter while performing these operations?
Thanks in advance for any advice on this issue.
I'm using SubSonic 2.2 by the way....
From what I've been able to test so far, I can't see an easy way to achieve what I'm trying to do.
The ideal situation for me would have been to generate SubSonic objects using SQL Server for example, and just be able to switch dynamically to MySQL by just creating at runtime the correct Provider for it along with its connection string. I got to a point where my app would correctly connect from SQL Server to a MySQL DB, but there's a point where the app fails since SubSonic internally generates queries of the form
SELECT * FROM dbo.MyTable
which MySQL doesn't support obviously. I also noticed queries that enclosed table names with brackets ([]), so it seems that there are a number of factors that would limit the use of one Provider along multiple DB engines.
I guess my only other option is to sort it out with multiple generated providers, although I must admit it does not make me comfortable knowing that I'll have N copies of basically the same classes along my project.
I would really love to hear from anyone else if they've had similar experiences. I'll be sure to post my results once I get everything sorted out and working for my project.
Has any of this changed in 3.0? This would definitely be a worthy reason for me to upgrade if life is any easier on this matter...