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Overview
Wayfast Datasets allow us to connect a page with a data source like a database or an API. Databases are one of the Wayfast Pillars. Wayfast Application Project’s are mostly used to interact with data sources and Datasets are the mean to achieve that goal. As a general rule we suggest using Stored Procedures to interact with databases but Datasets can run ad-hoc queries too.
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Today we are going to review how to execute a store procedure for reading data and displaying it in a Grid.
Preconditions
Before we start, this lesson assumes the following preconditions:
We already have a project. Let’s reuse our Hello World Project.
We need an active requirement so we can create objects in our database.
This lesson assumes you already know what a stored procedure is. If you don’t you can read about them here.
Step 1: Associate an instance
First let’s open Wayfast in a web browser and navigate to “Databases” menu then “Instances” submenu.
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The list of database instances associated to the project will be updated and now we are ready to create or attach a database.
Step 2: Create a database
Now we can navigate to “Database” submenu where we can see the list of databases related to this project.
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The list of databases will be updated indicating our DB was created successfully.
Step 3: Create database object and update Wayfast DB Model
Let’s connect to the project’s database using SQL Server Management Studio.
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Once the popup closes all new database objects are available in wayfast.
Step 4: Create a new Dataset
Go to “Project Pages” at the top menu and create a new page.
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Now that we have with our data source let’s see how display it in the UI.
Step 5: Connect a Dataset with a Grid
For displaying the list of roles we are going to use the grid control.
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| Info |
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You can find more details regarding the properties on “Grid Column” control lesson. |
Execution Types
One of the key details we need to understand about Datasets is the “Execution Type”. This field tells Wayfast when we want to execute this query. The first time we display the page, every time load the page or based on another control’s execution. This will impact the time it takes to load your page and how it is perceived by the end user. Let’s review these options in detail:
Execution Type | Description |
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Pre | Loads the dataset the first time the page is loaded. If there are control events associated to this dataset those events will trigger this dataset refresh too. This option will increase the initial load but will prevent from calling loading this dataset many times which will improve page’s responsiveness. |
Post | Runs upon another associated control’s events. For instance, you could use this option when you need to load the list of states based on the country selected on a dropdown. |
On-demand | Loads the dataset on every post back. This means every time the page interacts with the server. This is the most expensive options but may be required in some scenario were your data is prone to change frequently. |
Recap
In this lesson we created a database, a stored procedure, a page and a dataset to connect the page with the stored procedure. Then we created added a grid to display the values from the stored procedure.
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