I have created a table on my app. On the next build I am adding some more column and changing the name of one column.
Because the table is already created it will not create the table again, hence the changes are also not get reflected.
How to deal with this problem? please help me..
Related
I am using visual studio with sql server, i am in a middle of a practice and faced a major issue.
The issue was in the first place, when i was creating a product table , by mistake i mistyped as a categoryId ctegoryId, and later i recorrected it by thinking its over.
And now I am almost done with the identity scaffolding when updating my database, I am facing such an error. and I've tried all ways to update it by myself but failed.
I need an expert guidance so I can continue my path till the end.
I do appreciate any solution from your side.
Thanks indeed [Migration error "Each Table must be unique"](https://i.stack.imgur.com/tB3iT.png)
Just to let you know, I have deleted my migration and reinstalled again without[NotMapped]in my product table"categoryID" and it worked back normally.
I am working on a iOS mobile application using Xcode as the IDE and Swift as the language of choice. I added a column to the SQLite database that interacts with my application but unfortunately when I attempt to perform any database operations through the application the column is not recognized.
The following error is sent:
DB Error: 1 "table xyz has no column named column_name"
When I added the column I also increased the database version or user_version in SQLiteStudio.
Is there something else I should be doing to cause the application to recognize the changes? I know uninstalling and reinstalling would work but that is not an option of course as I cannot lose the data currently housed in the database. My other idea was to put all the data in temporary variables or something like that, drop and recreate the tables and reinsert the data. I wasn't sure if this was a good course of action though. Any help with this is appreciated.
I was given an alredy made project, I don't know if it is code or db first.
My problem is that when I try to remove row from one table or from some other one, it tells me there is a reference with other table and it can't delete them.
I can delete them from the db just fine so there must be something locking them in the code. If someone can give me any tip on where to look it would be helpfull, thank you !
Here is a screen shot of my code:
Here is a screen shot of my database structure:
I have accidentally deleted data from __MigrationHistory table and I tried to make migration new tables and column changes to db. At this time EF6 show me an error
"There is already an object named 'xxxx' in the database.".
I tried the way by using this command and there is no effect on table column changes.
Add-Migration MyMigration1 -IgnoreChanges
Update-database -Force
There are many recommendation about this for recreating db or another else. But those ways might be effect data losing to my db which contains a huge size of tested data and I can't able to lost any data. How to solve this error by without losing any data. If anybody please...
Update
Finally I found the solution to solve my problem. I am not sure it's a prefer way to solve such kind of problems but it's worked for me.
I cleaned data from __MigrationHistory table,tried to migrate new db and I copied data from __MigrationHistory of new db to my old db, then I set AutomaticMigration true and run update-database command and the problem was solved.
I'm not sure if its good approach to fix that but it worked for me.
I just did insert into that table with proper version and names of the already applied migrations, I did it in EF Core and it works actually, but please wait for somebody to comfirm that what im writing about.
The problem I see there is that you need two more fields to be filled (in EF Core theres only two columns) but I think that you can receive them using for example SQL Profiler
How do you update the database every time there is a fresh install/reinstall?
Looked in the docs, can't find anything - so what ends up happening, if I have changed my models, I will get a SQLlite error upon a fresh update.
Thanks
I think you can use :
Titanium.App.version
It will give you app version(Store it), at the time of initialization of your app check the current version.If it does not matches the one you have stored, just delete and recreate the database.
check out the Documentation here.
Hope it helps.