What is the correct approach to delete custom doctype in Frappe? How to migrate the same in other servers and also what about database tables? Do we need to manually drop them?
Currently for me the deleted doctype’s still persist in the server after bench migrate. Please can someone help me in this?
When you delete a custom doctype, it will just delete the entry from doctype table. Also, there is a doctype called Deleted Document. All the deleted doctypes will be tracked here automatically.
By default, Frappe doesn't drop the tables from database. If you are sure that you don't need that data, you can manually drop those changes.
In my experience you best don't bother with the tables in the database. Let Frappe keep track of this, don't interfere by dropping tables or altering tables.
Look at it like this:
If you are using a database system you don't bother what the database system does on the filesystem to organize itself.
If you are using Frappe you don't bother what Frappe does in the database system to organize itself.
When it comes to deploying your Doctypes on the next stage (QS, Production) you use "bench export-fixtures" to export and "bench migrate" to import your changes into your targeted Stage.
Don't create your own SQL-Scripts!
Related
There is plenty of documentation out there for looking up what content DB a site collection uses in SharePoint. However, I'm looking for the reverse. I have a specific DB, and I need to know where (what URL's) it's content is referenced or displayed.
We have a DB that has been partially corrupted and in need of restoring. It appears the only clean backup we have of it is relatively old. However, at first glance the library we know to be using it is lightly used. There has been no new content added to it since our backup was taken.
I am looking for a way to confirm that restoring from this backup wont unknowingly overwrite some critical data somewhere else.
In doing more digging, I did find another SO post that was able to get me the information I needed.
How to see all site collections in a specific content DB
-ContentDatabase contentdbname | select url, #{label="Size";Expression={$_.usage.storage}}
In navigating to the returned URL, I found recently added data. So that now rules out the restore.
I wanted to know something which is very disturbing for me. i.e.
Lets say I have an App. which is in the Appstore and running fine.
This App. has a local database with lets say 5 tables.
I update this App. and add 2 more new tables, which makes it a total of 7.
When the previous app version users will upgrade to the newer version. Will the database be updated also for the previous version users ?
If yes ?
then will the previous data will be removed.
If not
then the code will obviously make some crashes as it is going to need the new things which are not replaced.
Waiting for your precious comments.
It will all depend on your database. If you are using CoreData, you can migrate the users data into the new database and structures. All the information for your data model is stored in the .xcdatamodel class for your project. It isn't bundled into your code the way other files are.
The part you would need to look into is the Model Versioning Identifier. Here you will be able to increment your MOM, Managed Object Model.
You can also migrate the data over as well. I would review Apple's documentation on CoreData with focus on versioning and migration. Good luck.
Apple Core Data Versioning
If the database is based on coredata then you will need to use .
But if you are using sqlite DB
Then you can save the version number of your app into your db and whenever database is called(with new installation/upgrade), compare the version against the expected version If new version > older version then change the schema (this is needed if you would have changed the schema of your database) with using SQL ALTER statements and update the app version number. so whenever user is going to update or fresh installation, it will check the new version with your older version,
if it differ then
update schema,
and if its same
no need to make any changes.
If you would not have made any schema related changes (for example adding new column..) then you do not need to worry, user will not lose the data.
The contents of the documents directory is left unchanged. The contents of the .app bundle is completely replaced with the new version.
If you store your database in the documents directory and it is modified by the application, you will need to perform some migration to upgrade to the new version. If it's just a read-only database, you can copy over it with the new database.
It depends on where database is placed. All files in application bundle will be replaced. Files in Documents directory will remain intact unless you overwrite them...
Where do you store your database?
What i consider a good approach is to place database in bundle then on first run copy it to documents directory so that you gain RW access.
In your updated application you can check if database exists in Documents read it and update tables to new version, if not then just copy file from bundle to new location.
Unlike most sqlite apps where developers don't want to overwrite data in a sqlite database, I'm trying to enable an app to overwrite all data with future updates. The sqlite database will have the exact same name and have the same tables, I just want to be able to update the data contained in the database without making users delete the app and reinstall it. Is there an easy method to do this?
Thanks in advance!
A SQLite database file is just a normal file, so no special steps are needed. Get the path or URL to the file, and use NSFileManager's -removeItemAtPath:error: or -removeItemAtURL:error:. Then create the new database the same way you created the old one.
I have some general questions about iphone app updates that involves sqlite db.
With the new update does the existing sqlite db get overwritten with a copy of the new one?
If the update doesn't involve any schema changes then the user should be able to reuse the existing database with their saved data, right? (if the existing database doesn't get overwritten from 1 above )
If there are some schema changes, what's the best way to transfer data from the old database into the new one? Can some one please give me guidelines and sample code?
Only files inside the app bundle are replaced. If the database file is in your app's Documents directory, it will not be replaced. (Note that if you change files inside your app bundle, the code signature will no longer be valid, and the app will not launch. So unless you are using a read-only database, it would have to be in the Documents directory.)
Yes.
What's best depends on the data. You're not going to find sample code for such a generic question. First, you need to detect that your app is running with an old DB version. Then you need to upgrade it.
To check versions:
You could use a different file name for the new schema. If Version2.db does not exist but Version1.db does, do an upgrade.
You could embed a schema version in your database. I have a table called metadata with a name and value column. I use that to store some general values, including a dataversion number. I check that number when I open the database, and if it is less than the current version, I do an upgrade.
Instead of creating a table, you could also use sqlite's built-in user_version pragma to check and store a version number.
You could check the table structure directly: look for the existence of a column or table.
To upgrade:
You could upgrade in place by using a series of SQL commands. You could even store a SQL file inside your app bundle as a resource and simply pass it along to sqlite3_exec to do all the work. (Do this inside a transaction, in case there is a problem!)
You could upgrade by copying data from one database file to a new one.
If your upgrade may run a long time (more than one second), you should display an upgrading screen, to explain to the user what is going on.
1) The database file isn't stored as part of the app bundle so no, it won't get automatically overwritten.
2) Yes - all their data will be saved. In fact, the database won't get touched at all by the update.
3) This is the tricky one - read this fantastically interesting document - especially the part on lightweight migration - if your schema changes are small and follow a certain set of rules, they will happen automatically and the user won't notice. however, if ther are major changes to the schema you will have to write your own migration code (that's in that links as well)
I've always managed to get away with running lightweight migrations myself - it's by far easier than doing it yourself.
What I do is that I create a working copy of the database in the Documents directory. The main copy comes with the bundle. When I update the app I then have the option to make a new copy over the working copy, or leave it.
I'm developing an application and I'm using SQLite as my database storage.
I want to add and update the sqlite database throughout my application duration, so i copied it to the documents directory so i can do all kinds of stuff with my database except only selecting from it.
But since I'm developing "time", my database changes frequently (the database architecture is made by another developer) through the process
On the iPhone i'm checking
if the database exists in the documents directory
(if not) copy it to it.
use that database
but when i want to update my database ( i made in a separate sqlite manager ) it fails through the process of copying the newer version because i'm only checking if the database exists.
Does anyone of you guys experienced the same kind of problem ? and what did you do to pass this kind of problem ..
my only idea was to create a settings table and hold a row that check's for a version number of the database..
Is there also a way to edit the sql file from the documents directory in any sqlite management tool ?
or are there better solutions ?
What i did in my app:
- First i do the same thing. Check whether DB is in Documents or not.
- Then i check the previously installed version: small text file in documents tells me this
- If there is a need of an update, i merge the databases: the one in /Documents with the another one from app bundle.
- In my case i need to merge. In yours may be you can just copy over, if user doesn't change it.
What I do is create a series of sql scripts that are capable of upgrading from a previous version 1.sql, 2.sql, 3.sql, etc. When i open my database i query the version from a settings table and compare it with the newest .sql file i've found in my application bundle. If there is a newer version i begin running the .sql scripts until i have encountered the latest version. This has worked out pretty well for me on a couple of projects now.
Did you try to delete application on iPhone, and after that to deploy application again?
What I do is similar to what you did, except I added a small second table to the database. This database just contains one record - a database version number. So you start with version 1 in this database table. Then, when you change the structure, you update this version number to 2. In your startup code, check to see if the database exists. If so, check the version number of the database. If the version number of the database matches what you expect, just continue. If it's less than what you expect, call some code to upgrade the database to the current version and then continue.