I am using Beego framework in Golang. Whenever I add new table or column to the database, I want the code to do the migration. Is there any flag I can specify in code to migrate the database automatically in new release?
I don't want to run this bee migrate -conn="username:password#tcp(127.0.0.1:3306)/mydb" whenever I make db changes.
I think you want to use orm.RunSyncdb:
err := orm.RunSyncdb("default", false, true)
See Documentation: https://beego.me/docs/mvc/model/orm.md#generate-tables
Related
I am writing a project which needs to scrape data from a website, I am using pyspider, and it runs automatically every 24 hours(scraping the data every 24hours). Problem is , before writing the new data entry into the dB, I want to compare the new data with the existing data in the dB.
Is there a tool/lib I can use?
I am running my project on aws, what’s the best tool I can use to work with aws?
My idea is to set up some rule for the data to update/insert into the dB, but when the new data is somehow conflict with rule then I will be able to view the data/scrape log（where the tool will label it as pending）and waiting for admin to do further operation.
Thanks in advance.
[List of data compare, synchronization and migration tools.]https://dbmstools.com/categories/data-compare-tools
visit there. it might be helpful
I haven't found in documentation anything except "syncdb" command which create database tables from scratch. Is there any command to create and run migrations based on ORM model? Like in django? Add field, change type, etc.
No, orm.RunSyncdb(name, force, verbose) and it's command line equivalent only do a small subset of what tools like django's south can do.
Beego's orm can:
Create new tables from scratch
Drop all tables (force = true)
Add new columns as you extend your model
You need to handle dropping columns and any changes to the column parameters used to initially create the table.
Sadly beego doesn't include this feature, but no framework in go (as of today) does.
Instead they all relay that to other libraries to handle.
What you can do however is use goose for migrations:
https://bitbucket.org/liamstask/goose
or any other migration library as discussed in the following thread:
http://www.reddit.com/r/golang/comments/2dlbz5/database_migration_handling_in_go/
Remember that due to the modularity of beego you can also use any another orm (like gorm).
Feel free to look for : avelino/awesome-go in google if you want a list of tools/libs around the go ecosystem.
Yes, you can create migrations in beego now. Example, If you need to create a new table, you can start by creating a new migration file using the bee tool:
bee generate migration create_user_table
This command will create a file inside database/migrations folder. The file name contains the date, time and name of the migration.
For further details you can check this article https://ncona.com/2017/10/database-migrations-in-beego
I'm working with Django and I added a new model variable meaning that I need another column in my sqlite3 data base.
I have heard that I'm supposed to use sqlite> , but I am really confused when I start to use it. So, if that is part of the solution, can you be very specific on what to do?
thanks
MORE INFO:
my app is called "livestream" & and my class is "Stream"
I added the model "channel"
returns ---->
DatabaseError: table livestream_stream has no column named channel
You can ALTER TABLE to add a new column in Sqlite3 but not rename it nor drop it. Sqlite3 is a very useful database for bootstrapping your app. But sooner or later, you will need to change to a more robust/flexible database engine, say MySql or Postgresql.
Every time you add a new column to your models using Sqlite, you will need to recreate the schema (as far as I know, when you do migrations with Sqlite to add new columns, south complaints. see below). An approach I like more is use MySql with Django-South from the beginning, where I'm not sure about every aspect of my database.
Django South is an app for doing database migrations. It's very useful and the docs are a good starting point for beginners.
Every time you should make modifications to your database, you should consider them as migrations and use South.
Hope this helps!
Im currently developing a servlet homepage (spring + hibernate + mysql).
Im at the moment using the Hibernate property hibernate.hbm2ddl.auto set to update.
This is working fine and Hibernate creates and updates my tables.
However, Ive have read on multiple places that this is not recommended in production and that it is unsafe.
But if I dont put this option my tables is not created, and I really don't want to create my tabels manually on the server. I got limited time working on this alone.
How is this usually done? It's seems like it is quite much work to add all tables manually imo.
In production, you typically have already existing tables with a large amount of data that you don't want to lose, and that you want to migrate to the new schema. Hibernate can't do that automagically for you. It doesn't know that the data that was previously in column A must now be in the new column B.
So you'll need to create a migration script. Of course, you can use Hibernate to generate the new schema for you in development, see what the differences with the old schema are, and create your script thanks to that. But yes, having an app in production and migrate it needs some work to be done.
I have a Django project with multiple apps. They all share a db with engine = django.db.backends.postgresql_psycopg2. Now I want some functionality of GeoDjango and decided I want to integrate it into my existing project. I read through the tutorial, and it looks like I have to create a separate spartial database for GeoDjango. I wonder if there is anyway around. I tried to add this into one of my apps' models.py without changing my db settings :
from django.contrib.gis.db.models import PointField
class Location(models.Model):
location = PointField()
But when I run syncdb, I got this error.
File "/home/virtual/virtual-env/lib/python2.7/site-packages/django/contrib/gis/db/models/fields.py", line 200, in db_type
return connection.ops.geo_db_type(self)
Actually, as i recall, django.contrib.gis.db.backends.postgis is extension of postgresql_psycopg2 so you could change db driver in settings, create new db with spatial template and then migrate data to new db (South is great for this). By itself geodjango is highly dependent on DB inner methods thus, unfortunately, you couldn't use it with regular db.
Other way - you could make use of django's multi-db ability, and create extra db for geodjango models.
Your error looks like it comes from not changing the database extension in your settings file. You don't technically need to create a new database using the spatial template, you can simply run the PostGIS scripts on your existing database to get all of the geospatial goodies. As always, you should backup your existing database before doing this though.
I'm not 100%, but I think that you can pipe postgis.sql and spatial_ref_sys.sql into your existing database, grant permissions to the tables, and change the db setting to "django.contrib.gis.db.backends.postgis". (After you have installed the deps of course)
https://docs.djangoproject.com/en/dev/ref/contrib/gis/install/#spatialdb-template
I'd be interested to see what you find. Be careful, postgis installation can build some character but you don't want it to build too much.
From the docs (django 3.1) https://docs.djangoproject.com/en/3.1/ref/databases/#migration-operation-for-adding-extensions :
If you need to add a PostgreSQL extension (like hstore, postgis, etc.) using a migration, use the CreateExtension operation.