Is there a way to get all the SQL change script of the object context?
Note: I am not talking about ObjectQuery.ToTraceString();
No unfortunately there isn't anything 'in' the product and available directly off the ObjectContext.
However you should take a look at Jarek's TracingProvider, that injects a layer between the EF and SqlClient to do logging etc.
Read about it here.
Related
From what I have looked at so far, I am guessing the answer to this question is "no" but I thought I would ask in the event that I am missing something.
I have looked at the new RLS (row-level security) feature of Azure SQL. One of the things that needs to be done is to set the (user) context before executing a SQL statement. Since I am also looking at entity framework, my question is whether or not I can embed or inject something like "EXECUTE AS USER = 'User1'" into the SQL that is generated by entity framework.
Is this something that is possible? I know I can execute custom SQL but I was looking to set the code up in one place and have it run the statement for all generated SQL.
may be this EF6 feature can help, and more particularly the interception interface by the IDbCommandInterceptor.
Not clear about the hability to change the generated sql but may be.
Otherwise, have you tried a context.Database.ExecuteSqlCommand("EXECUTE AS...") ?
Create a new connectionstring using the user if you need to, or, you can modify the connectionstring used by DbContext.
I'm using the SQLite provider for Entity Framework 5 but it doesn't support CreateDatabase and thus cannot auto create the database. (Code First)
Is there a way I can obtain the Model schema at runtime so that I can create the SQL "CREATE TABLE" command myself?
If not at runtime, some other way to obtain the schema so I know how to create the table properly?
Thanks!
A) As for obtaining the model schema at runtime part
(all are earlier posts of mine)
See this one How I can read EF DbContext metadata programmatically?
And How check by unit test that properties mark as computed in ORM model?
Also this one for a custom initializer Programmatic data transformation in EF5 Code First migration
Having said that...
The problem I see is where and at what point you actually have the data available.
Actually I'm quite sure you won't be able to do that at any time.
Because to be able to extract that info you need to have a DbContext running - so db has to be constructed etc. etc.
In the initializer maybe - but using different ways to get that info - the above is not available.
B)
The other way would be to go the way of implementing a provider, generator etc. (e.g. this post).
That way you should get all that info just at the right time from the EF/CF itself.
However I haven't played with that much.
For more info you can check the EF source code
This is more of a 'gathered info' so far - in case it helps you get anywhere with it. Not really a solution. I'll add some more tomorrow.
EDIT:
To get the real database metadata, look into the other DataSpace, this should get you to the right place...
(note: things tend to get less exact from here - as obviously there isn't the right official support)
var ssSpaceSet = objectContext.MetadataWorkspace.GetItems<EntityContainer>(DataSpace.SSpace).First()
.BaseEntitySets
.First(meta => meta.ElementType.Name == "YourTableName");
If you look up in debugger, Table property should have the real table name.
However, reflection might be required.
How I can read EF DbContext metadata programmatically?
How check by unit test that properties mark as computed in ORM model?
Programmatic data transformation in EF5 Code First migration
Entity Framework MigrationSqlGenerator for SQLite
http://entityframework.codeplex.com/
Entity Framework - Get Table name from the Entity
ef code first: get entity table name without dataannotations
Get Database Table Name from Entity Framework MetaData
http://www.codeproject.com/Articles/350135/Entity-Framework-Get-mapped-table-name-from-an-ent
Does anyone know why LinqPad cannot autogenerate an Entity Framework context object (like it does with Linq-to-SQL)? It seems I have to create an assembly containing an EF context and then reference the assembly in LinqPad. But I don't need to do this with L2S.
Thanks very much.
LINQPad uses LINQ-to-SQL for automatic data contexts because it's lighter and faster. LINQ-to-SQL also generates better SQL in many cases and allows arbitrary functions in the final projection.
It wouldn't be hard, in principle, to write a driver for Entity Framework. The reason it isn't present as an option is lack of demand.
If you wanted, you could implement EF support seamlessly as a third-party driver. The only tricky thing to implement is supporting every version of EF.
As the title says, how do I view the SQL generated by Entity Framework from within my code? I'm running into an error where the EF is crashing because a field is generated by the database (a DateTime field), and I thought I set it to know that the store is generating it via StoreGeneratedPattern, but it's still crashing, so I would like to see what exactly it's trying to push up to the database.
P.S. I've only been using EF for about an hour now... Switching from L2S.
Since you don't have Sql Profiler, your best choice would be LINQPad. You can use your existing assembly.
Click Add connection -> Use a typed data context from your own assembly -> Entity framework and select your dll.
You can write queries directly against your model (or copy-paste from your code). Select the SQL 'tab' under the query window to view the generated SQL code.
You can use the Entity Framework Profiler (EFProf). It's not free, but there's a 30-day trial available. It does a lot more neat stuff besides showing you the SQL statements.
Generally, you should always use SQL Profiler to see the SQL statements that being submitted by EF into your database.
Also, I think you misunderstood about what StoreGeneratedPattern is. If you look at its possible values inside the model, you'll see that it has identity meaning that the value will be generated (by the database) when the row is inserted and will not otherwise change. The other options are Computed, which specifies that the value will be generated on inserts and updates, and None, which is the default.
So EF will not generate that DateTime field on the fly for you, you need to manually create it and then update your model from database so that EF will generate appropriate metadata to work with it at runtime.
The free AnjLab Sql Profiler will work if real SQL Profiler is not available because you're using SQL Server Express: http://anjlab.com/en/projects/opensource/sqlprofiler. It's not quite as nice as the real thing but it gets the job done well enough.
One solution would be to capture the network traffic and have a look at the data on that level. Microsoft Network Monitor does a good job of this.
Of course, that only works if you're using a separate DB server, and the connection is not encrypted.
This question is an extension of another question, but I think it warrants its own thread. See See Silverlight Question
I have a stored procedure (SQL 2005) that returns a dynamic data set (different columns/schema) each time it is called.
I want to consume this in Silverlight 3.0 so I need to somehow wire this up using Entity Framework and RIA Services. I also need this to be Bindable (Silverlight Grid) so I need these dynamic columns to be accessible via properties (grid limitation). Any ideas?
In the currently shipping version of the Entity Framework, the only type of stored procedures you can map are those which return entity types. The mapping is done, generally, before you compile, although it seems at least theoretically possible to generate Entity Framework metadata at runtime.
Therefore, I see a few choices.
Give up on the whole idea of consuming a procedure which does not return a defined schema. You will never be able to map such a procedure before you compile.
Dynamically generate EDMX at runtime in order to map an entity type to the expected output columns of the procedure before you invoke. Note that the current version of the Entity Framework is a bit finicky about the columns a procedure returns; you can find documentation about this on MSDN.
In .NET 4.0, there are new features which allow you to inform the Entity Framework about your client schema at runtime without having to generate EDMX first. You might be able to leverage these features in order to map some entity type to the expected output columns of the procedure.
Again, in .NET 4.0, there may be support for procs which return scalar values. I can't remember if this is the case or not.
You can always get a standard database connection from the entity connection and execute the procedure directly, using regular SqlCommands. Unfortunately, this makes your code database-provider-specific, but it may be the simplest solution to your problem. Indeed, using such a procedure at all is already database-server-specific.
You might use a WCF web service wraper for accesing your SP and use the WCF service as data source Brad Abrams has a way to do that on his series of articles on RIA Services