I am attempting to build several apps for different use cases in our business. However many of them share data. Such as our Inventory app will use the same customer data as our field audit app, and many apps will need to access the dataset we made to hold SKU information.
As such, my question is, if app a, has a table with x information. can App b access the same table?
It could.
You can add a model to an AppMaker App to get information from external sources.
See the information here:
https://developers.google.com/appmaker/models/overview
Related
I am working on an asset tracking system that also manages the concept of "projects". The users of this application perform maintenance activities on their customer's assets, so they need an action log where actions on an asset start life as a task in a project. For example, "Fix broken frame" might be a task where an action would have something like "Used parts a, b, and c to fix the frame" with a completed time and the employee who performed the action.
The conceptual data model for the application starts with a Customer that has multiple locations and each location has multiple assets. Each asset should have an associated action log so it is easy to view previous actions applied to that asset.
To me, that should all go in one table based upon the logical ownership of that data. Customer owns Locations which own Assets which own Actions.
I believe I should have a second table for projects as this data is tangential to the Customer/Location/Asset data. However, because I read so much about how it should all be one table, I'm not sure if this delineation only exists because I've modeled the data incorrectly because I can't get over the 3NF modeling that I've used for my entire career.
Single table design doesn't forbid you to create multiple tables. Instead in encourages to use only a single table per micro-services (meaning, store correlated data, which you want to access together, in the same table).
Let's look at some anecdotes from experts:
Rick Houlihan tweeted over a year ago
Using a table per entity in DynamoDB is like deploying a new server for each table in RDBMS. Nobody does that. As soon as you segregate items across tables you can no longer group them on a GSI. Instead you must query each table to get related items. This is slow and expensive.
Alex DeBrie responded to a tweet last August
Think of it as one table per service, not across your whole architecture. Each service should own its own table, just like with other databases. The key around single table is more about not requiring a table per entity like in an RDBMS.
Based on this, you should answer to yourself ...
How related is the data?
If you'd build using a relational database, would you store it in separate databases?
Are those actually 2 separate micro services, or is it part of the same micro service?
...
Based on the answers to those (and similar) questions you can argue to either keep it in one table, or to split it across 2 tables.
I am new to Google App maker and I don't have a lot of experience with coding either (sorry :/). Since App maker is marked as low-coding app builder tool, I assumed it was not that hard to make a very simple app with it. However, for me it is.
I need to make a simple app for demonstrations purposes only (so Cloud SQL and other complex database solutions are not in my interest here). I want to make it using calculated models (correct me if I am wrong, calculated models are just temporary solutions, since apps need to have like real databases to be fully functional?).
My app is basically made of 2 datas: 1) Employees and 2) Departments
-> Fields for "Employees" are: First name, Last name and Department.
-> Field for "Departments" is just Department name.
My app is supposed to look like this:
1st page: Table with current employees that has a button to add new employee,
2st page: Table with all department names (e.g. marketing, finance...) that has a button to add new department name,
3rd page: Form that opens when I click on add new employee button in which I can insert their first name, last name and from drop down menu choose department,
4th page: Form that opens when I click on add new department button in which I can insert new department name.
5th page: Form (or some other widget, not sure here) that has option to insert first and last name in order to find out what department that employee is assigned to.
I tried to make first 4 pages, but I end up with forms that I cannot insert anything into them. 5th page is still too much for me.
I hope you understand my struggles and if you know how to do it please share your knowledge. Thank you very much!
Calculated models are kind of like SQL views - they are not necessarily for temporary solutions. Every time you load a calculated model the script you write under that model's datasource is ran. That script usually loads data from an external source (I.e. grabbing stock prices from an API, loading data from an external SQL server, or generating random placeholder data).
You could use the cloud SQL models for this application that you are building - your table with all department names that is supposed to be displayed in the second page could just be a cloud SQL table with one single field for a department name.
I suggest you work through the example apps so you can get a better understanding of how the different components work. Here is a link to one for you to get started.
In short, you're going to create a few models to store information (I suggest using cloud SQL as the calculated models will require code whereas cloud SQL is more plug and play through app maker's bindings). Before you create any pages try to lay out how your databases will look as that will dictate how you set bindings or program your scripts.
Asking to completely make what is essentially a combination of the tutorials already provided by Google is pretty counter intuitive - you should ask more specific questions in regards to implementation.
As for App Maker being a low-code environment, that's only partially true. For very, very simple apps (think glorified forms) you will need only a couple lines of code and can probably do everything through drag-and-drop. However, anything more complicated than a simple form will almost certainly require a good chunk of actual code. There are plenty of resources online to learn Javascript.
You might want to try a google partner like AppSynergy for building stuff like this. It might be overkil for what you need (or maybe not if you intend to build a lot more stuff).
I've been struggling for a couple of days trying to figure out the best way to design a database of a large data set on Firebase, I even wrote a question on database administration site.
I came up with a design, I don't know that's what's called denormalized data or not. I want to minimize querying time of data and also not making inserting/updating data so hard.
Here's my design:
Is that the right database design for this kind of data ?
(Please check my question at database administration site for more details about the nature of the data).
But also here's a short description of the data nature:
So I have an affiliator_category which maybe banks, clubs or organisations. And each category contains a number of affiliators and each affiliator contains number of stores divided into store_category, each store has a number of offers.
And for the user side (the one who do the shopping). A users has a number of memberships in several affiliators, and a number of spendings he/she does.
I have a Plone 4 site which contains a lot of users and groups which are stored in the ZODB. Over time, we added some functionality which uses relational data (in a PostgreSQL database); some tables have fields which contain user or group ids.
However, currently the users and groups are defined in ZODB rather than the RDB, so we don't have proper foreign keys here. Thus, the obvious idea is to migrate the user and groups data to the RDB - those who/which are used by the Plone site, at least; I assume emergency users need to be an exception to this (but those are no members of any groups anyway).
Would this be a good thing to do?
Are there reasons to do it only partly, or should I transfer everything including group memberships? (Since memberships are stored as lists of users (and/or groups) with the containing group, I could imagine a reverse table which holds all groups a user is member of, and which is maintained by a trigger function.)
Are there any special tools to use?
Thank you!
imho it's based on what you want to achieve. In Plone you have PAS, so technically it doesn't really matter, where you put users, groups and user group relationships.
You can store users/groups in:
Plone (by default)
SQL - pas.plugins.sqlalchemy
LDAP/AD - Products.PloneLDAP
There are also many other plugins for AUTH, like RPX, Goolge+, etc.
You can enable, disable and modify the behabvior of every plugin thru PAS.
Does it make sense, to NOT use Plone users?
Of course, if you want to share user credentials (Example LDAP), or if you need the user informations in other Apps, etc.
Migration
Should be very simple if the PAS plugins you are using supports "Properties" and "User enumeration".
Get the data from one plugin and put the data into another one with a simple python script. Both supports the same API.
the tool you're looking for is https://pypi.python.org/pypi/pas.plugins.sqlalchemy/0.3
I've used this in a webportal where users are "shared" with a newsletter system.
I've 200 users and any problem.
I think the only "good reason" to store users in an external DB rather in zodb/plone is in a use-case like mine.
Have you ever think about "extend" plone users (ex. https://plone.org/products/collective.examples.userdata)? With plone.api you can easly manipulate users' properties in your code.
I'm currently in the process of creating a website/system and was wondering how I can create multiple versions of a table to then be used by many users. The reason for this is primarily due to the amount of information that is needed my each user. Another reason for doing so is a result of each information have been laid out to display the product code and other key information.
This is due to a main table setting a list of data for example prices of a product. To which the user then can set and store data in their own table to be used at a later date and referenced accordingly. Rather than creating multiple columns in the thousands I feel it would be better to simply create different versions of the table.
Instead of creating multiple table, why don't you not create seperate Views in Database based on your User and display that information in table.
Altought, its recommended to use the single same table, and add fields that allow to restrict some data for a particular user, there is some few cases that may be required to have several versions of the table, like the ones you mention.
I have work with a web app. that served several companies, with the same tables, fields, schemas, same web server & databased server, and yet the customers want it separated from other users.
Usually, you create several tables with the same schema, but different id. Your web app. must have a way to select which table or database you are going to use.
Be very careful with this approach, is very difficult to maintain, its better to use some programming techniques to control this scenario, like:
http://en.wikipedia.org/wiki/Multitier_architecture
That allows to have a lot of control over a database app. and allows to change a table or database with thesame schema.