I'm having an issue at the moment where, we have a database which was already created, so used ef scaffold to create a model of it - the schema the model was created against is called "xxxx-dev".
Now, this has been fine, but in preparation to go live, I created a new DB server and provisioned the database to be called "xxxx-live". Switched the connection string, and attempted a query against it, and got an error.
It seems that scaffolding has hard-coded the schema name into every table in the OnModelCreating call, for example:
modelBuilder.Entity<xxxx>(entity =>
{
...
entity.ToTable("xxxx", "xxxx-dev");
...
});
This is a bit of an issue as going forward, we might have multi-tenant sites based on the same database, and obviously the query overriding the connection string every query isn't a great experience.
Is there anyway to configure the schema name, either in the Scaffold, or at runtime? I've done a bit of searching around and can't seem to see a solution.
Thanks,
Related
I'am working on a Symfony app that provides a rest web service (simple HTTP Request with JSON).
That service check some rules and inserts few lines in two MySQL table (write only).
For optimize reason, even if Doctrine bundle is available, i use native MySQL Query (with bind params) to insert this lines.
My need is : If for any reason, the database is not available, write "runnables" queries into a log file.
The final purpose is that when database is back, i want to be able to execute directly the file's content on the database.
Note that there is no unique constraint (pk is a generated uuid) and no lock or transaction to handle (simple insert statements).
I write a custom SQLLogger, but when $connection->insert(...) is called, the connect fail before logger is called.
So, my question is : There is a way to get the final query (with binded parameters) without database connection ?
Or should i rewrite the mecanism that bind params into query and log it myself when database is not available ?
Best regards,
Julien
As the final query with parameters is build by the database, there is just no way to build the query with PHP and to be garanteed that the query will be the same as the database.
The only way si to build query without binded parameters, but this is clearly not a good practice.
So, i finally decided to store all the JSON (API request body) in a file if the database is not available.
So when the database is back, instead of replay SQL queries, i can replay the original HTTP query.
Hope this late self-anwser will help someone.
Best regards.
I've created an ASP.NET Dynamic Data Entities Web Application project with visual studio 2010.
I've added a ADO.NET Entity Data Model connected to a sql Server database.
The application works fine.
I'd like to handle an exception when deleting a row in a table that has a column which is a foreign key for another table.
The exception is :
The DELETE statement conflicted with the REFERENCE constraint "FK_name". The conflict
occurred in database "NAME", table "dbo.dbname", column 'Column_name'.
What I'd like to do is display a user friendly message to explain that the operation cannot be made before other rows in other table are delete.
I did some step by step debugging, but I can't find where the application does the database request, so that I can customize the code.
Thanks.
I did some research and i found two options :
- I can handle the delete directly with gridview attribute OnRowDeleting. This mean a lot of entity manipulation
- I can handle entity framework SavingChanges and check for entities on EntityState.Deleted, then check entity navigation properties and throw an explicit message if necessary. This works with a custom validation error to show user friendly message.
Using ASP.net 4.5, I created a membership database and set up some open auth providers. In the course of adjusting the database, I deleted the open auth tables (UsersOpenAuthAccounts and UsersOpenAuthData) - I can find no script to generate these items or any other way to regenerate them.
The ASP.Net membership libraries create a system table called __MigrationHistory. When these OAuth elements are created, it creates this table (if missing) and creates a record there which acts as a flag indicating that it is not necessary to create the db items. Delete the table, and the membership libraries will recreate the elements.
You will receive an exception indicating that the __MigrationHistory table is missing - ignore this error, as it will be recreated along with the other elements.
BUT BEWARE - __MigrationHistory is a table used by Entity Framework...you may jack it up in try to fix this, so keep a backup handy.
When we developers write data access code what should we really worry about if the application should scale well and handle the load / Hits.
Given this simple problem , how would you solve it in scalable manner.
1.ProjectResource is a Class ( Encapsulating resources assigned to a Project)
2.Each resource assigned to Project is User Class
3.Each User in the Project also has ReportingHead and ProjectManager who are also instance of User
4.Finally there is a Project class containing project details
Legend of classes used
User
Project
ProjectResource
Table Diagram
ProjectResource
ResourceId
ProjectId
UserId
ReportingHead
ProjectManager
Class Diagram
ProjectResource
ResourceId : String / Guid
Project : Project
User : User
ReportingHead : User
ProjectManager : User
note:
All the user information is stored in the User table
All the Project information is stored in the project table
Here's the Problem
When the application requests for Resource In a Project operations below are followed
First Get the Records for the Project
Get the UserId , make the request(using Users DAL) to get the user instance
Get the ProjectId, make the request(using Projects DAL) to get the project information
Finally assign Users and Project to instance of ProjectResource
clearly you can see 3 Db Calls are made here for populating single ProjectResource but the concerns and who manages the objects are clearly defined. This is the way i have planned to , since there is also connection pooling available in Sql Server & ADO.net
There is also another way where all the details are retrieved in single hit using Table Inner Joins and then Populating.
Which way should i really be taking and Why?
Extras:
.NET 2.0,ASP.net 2.0,C#,Sql Server 2005,DB on same machine hosting application.
For best performance and scalability, you should minimize the number of round-trips to the DB. To prove that to yourself, just run some benchmarks; it becomes clear very quickly.
One approach to a single round-trip is to use joins. Another is to return multiple result sets. The latter can be helpful in eliminating possible duplicate data.
I have two tables
Users (Userid, Name, PhoneNumber)
Applications (ApplicationsId,UserId, ApplicationName, ActiveDate)
Every user will have more than 1 application.
In Nhibernate using lazy loading I can get the users data along with all the applications for every user. So, I used to do something like user.applications[i].Applicationname to get all the applications.
But, Now how do i retrieve all the applications along with the users data using oracle commands. I know how to get one application using joins. But, how do i retrieve multiple applications and store it in a IList. Any help is greatly appreciated. Thank you.
First you should download the Oracle Data Provider for .NET in
http://www.oracle.com/technology/tech/windows/odpnet/index.html
after you make sure that you can open a connection to your oracle database then
define mapping file of your entities in Nhibernate and map table columns of your oracle table to .NET object. after that you can use the following code snippet to get the list of your entity from database
// create the query...
IQuery query = session.CreateQuery( "from Post p where p.Blog.Author = :author" );
// set the parameters...
query.SetString("author", (String) instance);
// fetch the results...
IList results = query.List();
You should define the (Post) entity and (Blog) entity to your mapping file and as you can see (Post) has relation to (Blog) entity which is defined in the mapping file too.