Views in Backendless Console are a powerful way to explore your data visually by composing datasets of related records in less time than writing queries.
View Designer is an interactive tool for creating Backendless Views. A
view is a virtual data table that supports only data retrieval. As the records in the underlying tables are added/modified/deleted, however, the view will automatically reflect these changes.
Views are designed to make it easier to visually explore and display the data in your Backendless Database. With a view, you can combine data from related tables, transform, aggregate, group, and condition data, and all of the complexity is handled through a user-friendly visual interface.
Once your view is created, you can use the API you are already familiar with to retrieve the View data exactly as you composed it.
If you’ve spent any time working in Backendless Database, you know that it is very feature rich. You can do a lot of different things with your data, such as retrieve relational data, massage it, aggregate it, rename properties, group, etc.
Previously, to take advantage of all these features, you had to understand how the APIs work. Now, you can simply do all of it visually by creating a view. Then, you simply use the built-in View Code Generator to plug the view’s query into your application.
Views make it easy to visually build queries for your data. With the View Designer, you instantly see the result of the query, making it easy to tweak and modify your query until it’s just right.
Since all views use the same underlying data, if the data is modified in the database, it will be updated in all views that utilize that data. All of your views can be saved so you can easily come back to them on a weekly or monthly basis to review the data as it develops.
For this article, we’re going to use an example database of fictitious movies. We have a table for films with a variety of relations such as category, actors, actresses, and language.
For more about Views, you can watch our five-part Views video playlist here.
To create a view, click the
+ icon just as you would to create a table. You will now be given a choice between creating a table or a view.
The view name can contain any characters including space, dash, etc,, and may be in any language. When a view is created, it shows up in a section called
To design a view, you simply selects the
+ next to the columns you want to use. For our first example, we will select the column
title from the
When a column is selected, the view automatically shows data for the selected column. The first column you select becomes the “root” column for the view. This means that any and all related tables in its tree (both children and the parent) will be used as the “context” of the view.
Once the context or “scope” of the view is established by identifying the root table, you can select the columns from any of the related tables.
Columns added to a view can be renamed using the aliasing feature. To create an alias, click the “label” icon. When an alias is assigned, the icon becomes green, otherwise, it is gray.
In our example, we want to display the column called
name from the related
category table. Of course, having a column called
name right next to a column called
title could be very confusing, so we’ll rename
Every column added to a view may have its own retrieval condition. A condition can be set for each individual column. To configure and manage column condition, click the “filter” icon in the column. When a condition is set, the filter icon is green, otherwise it is gray.
If you have multiple columns with conditions (filters), you can specify in the view how to group those columns. Grouping determines whether the view should treat each condition as an
OR when selecting and organizing the data.
Individual column conditions are sequenced together with the
AND operator. You can change the sequencing and grouping using the
Configure conditional column grouping interface.
Available column conditions include common SQL search functions. Unlike filtering your data in the Table view, in a view you don’t need to know any SQL syntax to get the results you seek.
Values for the columns added to a view can be “transformed” using functions. To configure a transformation, click the “double arrow” icon.
When a transformation is configured, the icon changes to green, otherwise it is gray. Functions available for transformations vary depending on the type of data of the column. Below you can see the functions available for a
STRING type column.
DATETIME type column. (As you can see, there are many options for this column type.)
Any column added to your view can be aggregated.
Let’s say we want to know how many actors are listed in the category Sports. We simply include those two columns in our view and a few clicks later:
If there is at least one column with an aggregation function, the “aggregated values grouping” icon will be enabled (it’s not required to be used). Clicking the icon opens up the “Column Aggregation” popup.
Let’s take our previous example. Now we want to see how many actors there are in every category that includes the letter
First, we change the conditions on the Category column. As you can see, all of the categories found are bunched together.
Now we need to click the grouping icon on the left-hand side. This will open the Column Aggregation popup.
Grouping can be done by any column. For our example, we will select
categories.name to group by the category name. The result of the grouping will look something like this:
In addition to the individual column conditions, a view may have a single (
Master) condition which applies to the entire data set.
In Backendless Console, you will see the following description of the Master View Condition:
The central context of the view is the table where the first column comes from. The condition can reference any column from any of the related tables.
What this means is that the Master condition will apply to the all tables in the view; you cannot filter the view based on an unrelated table using this condition.
Generate query code icon
</> opens up a popup with the code that can be used to retrieve the query. The popup contains two primary tabs:
Server-driven Query– code to fetch view data where the query is executed on the server
Client-driven Query– code (mainly
DataQueryBuilder API) which can be executed on the client-side to retrieve the view data
To learn more about the capabilities of Backendless Views, check out our Deep Dive series.
Views are a convenient way to display your data in a way that is easily readable for a human. We can’t wait to see the awesome things that you build with this new feature!
Thanks for reading and Happy Codeless Coding!