I am very new to Appcelerator, i've got my head around using Alloy to lay the content of my apps out, and have got to grips with using the Firefox extension to create an SQLite database. I'm stuck at putting the two together though. I've tried the Ti.UI.Database.Install but I'm not 100% which JS file to add that coding to, or where to copy the DB file to. I've followed a few threads and tutorials, tried putting the .db file into the resources folder, lib folder etc but keep coming up with errors. If someone could just talk me through the basic steps that would be great.
This is about using a predefined sqlite database in your app, meaning you want to install a db with preloaded records in its tables.
app/assets is a good place for your_database.sql;
then in app/alloy.js
Ti.Database.install('/your_database.sql', 'your_database')
finally configure the adapter attribute in your alloy's models with:
type: "sql",
db_file: "your_database.sql",
db_name: "your_database",
collection_name: "your_table_name"
Anyway, if you do not need to preload a database, you only have to define your models (here, in example, app/models/foobars.js) and configure their adapter with
type: "sql",
collection_name: "foobars"
This way Alloy will take care to create and install the database (including a foobars table) for you.
Related
I have a service running on my linux machine that reads data stored in a .json file when the machine is booting. The service then validates the incoming JSON data and modifies specific system configurations according to the data. The service is written in C++ and for the validation im using https://github.com/pboettch/json-schema-validator.
In development it was easy to modify the JSON schema and just adapt the data manually. I've started to use semantic versioning for my JSON schema and included it the following way:
JSON schema:
{
"$id": "https://my-company.org/schemas/config/0.1.0/config.schema.json",
"$schema": "http://json-schema.org/draft-07/schema#",
// Start of Schema definition
}
JSON data:
{
"$schema": "https://my-comapny.org/schemas/config/0.1.0/config.schema.json",
// Rest of JSON data
}
With the addition of the version, I am able to check if a version mismatch exists before validating.
What I am looking for is a way to automatically migrate the JSON data to match the newer schema version, if a version mismatch is identified. Is there any way to automatically achieve this, or is the only way to manually edit the JSON data to match the schema?
Since I plan on releasing this as open source I would really like to include some form of automatic migration so I can just ask the user if he wants to migrate to conform to the newest schema version instead of throwing an error, if a version mismatch was identified.
What you're asking for is something which will need to make assumptions to work.
This is an age old problem and similar for databases. You can have schema migrations generated with many simple changes, but this is not viable if you wish to translate existing data automatically too.
Let's look at a basic example. You rename a field.
How would a tool know you've renamed a field vs removed an old one and added a new one? It essentially, cannot.
So, you need to write your migrations by hand.
You could use JSON transformation tools like jq or fx to create migration scripts without writing it in code, which may or may not be preferable. (jq has a steeper learning curve but it's also very powerful.)
Currently my VDB DDL file is getting quite big. I want to split into different files using the following.
IMPORT FROM REPOSITORY "DDL-FILE"
INTO test OPTIONS ("ddl-file" '/path/to/schema1.ddl')
However, this does not seem to work.
Can the DDL file path be relative, how?
The schema test, can it be VIRTUAL?
Does "DDL-FILE" refer to "ddl-file"?
What should I put in my main VDB ddl and what should I put in my extra ddl's. Should the
extra ddl's contain server configuration details or should they be defined as a VDB.
I would like to see a working example on how to use this.
This will be used in a teiid springboot project where you can only load one main vdb file. It is not workable to have one very large ddl file.
I tried multiple approaches but it does not seem to work, either giving me a null pointer with no error codes or error codes that tell me nothing.
Also the syntax in Teiid 9.3 seems different:
IMPORT FOREIGN SCHEMA public
FROM REPOSITORY DDL-FILE
INTO test OPTIONS ("ddl-file" '/path/to/schema.ddl')
This feature is currently not implemented in Teiid Spring Boot. This issue is captured in https://issues.redhat.com/browse/TEIIDSB-219
Update: I added the needed code to master, should be available with 1.7 release meanwhile you can build the master branch and test it out.
In my local machine I use RStudio + Shiny to work properly.
Now that I have Shiny-Server installed on linux, but I do not know the Data generated by RStudiom.
how can I get Shiny-Server to read it?
Do not know what keyword query?
Thanks
Importing data in the server
As I see it, there are two ways to supply data in this situation.
The first one is to upload the data to the server where your shiny-apps are hosted. This can be done via ssh (wget) or something like FileZilla. You can put your data in the same folder as the app and then access them with relative paths. For example if you have
- app-folder
- app.R
- data.rds
- more_data.csv
You can use readRDS("data.rds") or readr::read_csv2("more_data.csv") in app.R to use the data in the app.
The second option is to use fileInput inside your app. This will give you the option to upload data from your local machine in the GUI. This data will then be put onto the server temporarilly. See ?shiny::fileInput.
Exporting data from RStudio
There are numerous ways to do this. You can use save to write your whole workspace to disk. If you just want to save single objects, saveRDS is quite handy. If you want to save datasets (for example data.frames) you can also use readr::write_csv or similar functions.
I'm curious what the point of the structure.sql file is. It seems to be updated and created every time rails migrations are run. So it seems to be a visual representation of our database. What else can it be used for?
When one runs structure:load, what does it do? What does it mean to load a structure file into a database? Why would you need to do that?
Should one be committing the structure.sql file?
Seems like your rails app is configured to use the sql schema format
#/config/application.rb
...
config.active_record.schema_format = :sql
...
the structure.sql is in place of a schema.db.
Running db:structure:load ( or db:schema:load) will load your entire database. You only need to do this when bringing on a new app instance from scratch. After awhile, your migration files will become quite lengthy and it will be better to do a load first, then a migration when bringing up a new app instance
I am setting up our project to integrate with a shipping platform called Endicia which has the ability to insert new rows into our database when a package is shipped.
How can I detect from python when a new row has been inserted?
My solution for now would be to query the DB every 30 seconds or so for new rows... is there another solution to send a signal from postgres to python?
You'd set up a custom command that is run by the manage.py file.
You'd put it in `yourapp/management/commands/' folder. Make sure to add an init.py file to both the management and commands folder or the command won't work. Then you create the code for the custom command.
Then, see this related question about running a shell script when changes are made to a postgres database. The answer there was to use PL/sh. You'll need to figure that part out on your own, but basically however you do it, the end result is that the script should call something like /path/to/app/manage.py command_name