I'm trying to find some nice work arounds for the issues of computed columns in code first. Specifically, I have a number of CreatedAt datetime columns that need to be set to getdate().
I've looked at doing this via the POCO constructors, but to do that I must remove the Computed option (or it won't persist the data), however, there is no easy to way ensure the column is only set if we are inserting a record. So this would overwrite the CreatedAt each time we update.
I'm looking to create an alter script that can be called after the DropCreate that would go through and alter various columns to include the default value of getdate().
Is there an event to hook into something like OnDropCreateCompleted where I could then run additional SQL
What would be the best way handle the alter script? I am thinking just sending raw sql to the server that would run.
Is there another way to handle the getdate() issue that might be more graceful and more inline with code first that I'm missing?
Thanks
You can just make custom initializer derived from your desired one and override Seed method where you can execute any SQL you want to use - here is some example for creating such initializer.
If you are using migrations you can just the custom SQL to Up method.
Related
Before anything, i must say this first: This table design is not my decision. We protest but to no avail, so please don't tell me, don't create a table like that.
We have a database with each table have a flag. This flag used to indicate which environment this row belong to, production or test data.
For server side, we have one variable which currently stored in ThreadLocal to indicate which environment this request belong to, same value as the flag in database.
Our requirement is that if my request belong to test environment then we must select only record belong to this environment. We would need to add a condition to every query we made to database, something like:
SELECT t FROM TABLE t WHERE t.flag = :environment
But we have to update every single query, update every object to set this flag before insert/update into database. This will require a lot of effort as our system already built long ago, not on progress. Also this will bring a lots of risk if someone forgot to add this to any new query.
So is there anyway to insert a condition to check this flag value for every query without have to manually edit the query string? Like an interceptor or something to put this condition in?
Which JPA provider?
With Hibernate, you could try using a #Filter.
Multitenancy could be another option, but probably an overkill in your scenario.
Finally, since you flagged the question with Oracle, perhaps the easiest approach would be to provide dedicated schemas (per environment) with views for every single table in your db, filtered by the flag column. Not sure if you're allowed to do that, though.
With some of the above, you would need a global entity listener to populate the flag field of your entities before they are persisted.
As far as I know, all QuickBase API calls are called using the following syntax: http://<quickbase>/db/<dbid>?
Is there a way to get the dbid field without navigating to that database table within QuickBase?
If the above is not possible, would anyone recommend anything other than creating another table that stores the IDs of the tables you want?
With the latter method, I believe I would only need to store one dbid and could pull down the rest (which I believe would still need to be user entered, but would be better than requiring them to change the code).
Thanks for the help!
API_GetSchema will return the list of dbids.
https://www.quickbase.com/db/<yourApplicationId>?act=API_GetSchema&apptoken=<yourApplicationTokenId>&fmt=flat
I have an custom entity which needs to have a case number for an XRM Application, can I generate a case number from the Service -> Case.
If this is not possible, how can I do this with a plugin, I've looked at the crmnumbering.codeplex.com but this doesn't support 2011, anybody outthere have a solution or should I rewrite it myself?
thanks
I've ran into this same type of issue (I need a custom # for an entity). Here's how you can do it:
Create an Entity called "Counter"
Add a field called "new_customnumber", make it a string or a number depending on what you want
Create a new record for that entity with whatever you want in the new_customnumber field (let's say "10000")
Create a plugin (EntityNumberGenerator) that goes out and grabs that record (you'll probably want to set the security on this record/entity really tight so no one can mess with the numbers)
On Create of the "custom entity" fire the plugin. Grab the value in new_customnumber save it to the "custom entity" (let's say in a "case" field) increment the new_customnumber and save it to the Counter entity.
Warning, I'm not sure how this is with concurrency. Meaning I'm not sure if 2 custom entities being created at the same time can grab the same number (I haven't ran into an issue yet). I haven't figured out a way to "lock" a field I've retrieved in a plugin (I'm not sure it's possible).
You will be unable to create a custom number for custom entities from the normal area you set a case number.
Look at the CRM2011sdk\sdk\samplecode\cs\plug-ins\accountnumberplugin.cs plugin. It's really similar to what you want.
Ry
I haven't seen one for 2011 yet. Probably easiest to write it yourself.
I've always created a database with a table with a single column which is an IDENTITY column. Write an SP to insert, save the IDENTITY value to a variable, and DELETE the row all within a transaction. Return the variable. Makes for a quick and easy plug-in and this takes care of any concurrency issues.
The performance is fast and the impact to your SQL server is minimal.
I am using Sql tables without rowversion or timestamp. However, I need to use Linq to update certain values in the table. Since Linq cannot know which values to update, I am using a second DataContext to retrieve the current object from database and use both the database and the actual object as Input for the Attach method like so:
Public Sub SaveCustomer(ByVal cust As Customer)
Using dc As New AppDataContext()
If (cust.Id > 0) Then
Dim tempCust As Customer = Nothing
Using dc2 As New AppDataContext()
tempCust = dc2.Customers.Single(Function(c) c.Id = cust.Id)
End Using
dc.Customers.Attach(cust, tempCust)
Else
dc.Customers.InsertOnSubmit(cust)
End If
dc.SubmitChanges()
End Using
End Sub
While this does work, I have a problem though: I am also using StoredProcedures to update some fields of Customer at certain times. Now imagine the following workflow:
Get customer from database
Set a customer field to a new value
Use a stored procedure to update another customer field
Call SaveCustomer
What happens now, is, that the SaveCustomer method retrieves the current object from the database which does not contain the value set in code, but DOES contain the value set by the stored procedure. When attaching this with the actual object and then submit, it will update the value set in code also in the database and ... tadaaaa... set the other one to NULL, since the actual object does not contain the changed made by the stored procedure.
Was that understandable?
Is there any best practice to solve this problem?
If you make changes behind the back of the ORM, and don't use concurrency checking - then you are going to have problems. You don't show what you did in step "3", but IMO you should update the object model to reflect these changes, perhaps using OUTPUT TSQL paramaters. Or; stick to object-oriented.
Of course, doing anything without concurrency checking is a good way to lose data - so my preferred option is simply "add a rowversion". Otherwise, you could perhaps read the updated object out and merge things... somehow guessing what the right data is...
If you're going to disconnect your object from one context and use another one for the update, you need to either retain the original object, use a row version, or implement some sort of hashing routine in your database and retain the hash as part of your object. Of these, I highly recommend the Rowversion option as well. Using the current value as the original value like you are trying to do is only asking for concurrency problems.
I am in the process building myself a simple Linq to SQL repository pattern.
What I wanted to know is, is it possible to set a default sort column so I don't have to call orderby.
From what I have read I don't think it is and if this is the case what would recommend for a solution to this problem.
Would the best idea be to use an attribute on a partial class on my model?
the default order is the clustered index on the table you are pulling from.
What are you wanting to sort on (without sorting on) ?
If you needed something other than having it sorted by the primary key, you could look at supplying a select statement for the table instead of using the runtime generated statement. Look at the properties on the table in the designer -- you should be able to override the runtime generated select, delete, and update statements. I don't personally recommend this, though, since I'm not sure how it will interact with other orderings. I think the intent is more along the lines of allowing you to use stored procedures if you want.
Another alternative would be to create a table-valued function or stored procedure that does the ordering the way you want and has the same schema as the table. If, in the designer, you drag this onto the table, you get a strongly typed method on the data context that you can use to obtain those entities according to the definition of the function/procedure instead of the standard select. Personally I think this introduces fewer maintenance headaches because it makes it more visible, but you do have to remember to use the method instead of the Table property for that entity.