# Exercise - Use collections and manipulate tables

Completed

In this exercise, you will practice using tables. You will create a collection, filter the collection, perform a lookup to the collection, edit a record in the collection, add a record to a collection, and remove a record from the collection.

## Create the collection of data

1. Sign-in to Power Apps.

2. On the Home screen, select Canvas app from blank.

3. Name your app New Collection App and click Create.

4. Select the Insert tab and add a button, and set its OnSelect property to this formula:

 ClearCollect(CityPopulations, {City:"London", Country:"United Kingdom", Population:8615000}, {City:"Berlin",
Country:"Spain", Population:3165000}, {City:"Rome",
Country:"Italy", Population:2874000}, {City:"Paris",
Country:"France", Population:2273000}, {City:"Hamburg",
Country:"Germany", Population:1760000}, {City:"Barcelona",
Country:"Spain", Population:1602000}, {City:"Munich",
Country:"Germany", Population:1494000}, {City:"Milan",
Country:"Italy", Population:1344000})

5. Press and hold Alt Key, and select the Button control. (This will create your collection and store all the information.).

6. Select the Gallery dropdown at the top and choose Blank vertical gallery and choose CityPopulations from the data source pop-up.

7. With the gallery selected, in the right pane, change the layout from blank to Title, subtitle, and body.

8. Select the Body of the first gallery item. Change the Text property of this control to:

"Population: " & ThisItem.Population


1. Add a label that reads "Population" and move it to the right of the gallery.

2. Select the Input dropdown at the top and choose Slider and put it under the label we created.

3. Select the slider and change the Min property to:

 Min(CityPopulations, Population)

4. Next, change the Max property to:

 Max(CityPopulations, Population)

5. Now select the gallery and change the Items property to:

 Filter(CityPopulations, Population>= Slider1.Value)


6. Now we will only be seeing records that are greater than the selected slider value. Move the slider around to see this in action.

## Use the LookUp and Patch functions

1. Add a label that reads "City" and place it under the slider.

2. Next, select the Input dropdown at the top and choose Dropdown and move it under the City label.

3. In the Items property of the dropdown, write the following:

 CityPopulations.City

4. In the OnChange property of the dropdown, put the following:

 Set(varRecord, LookUp(CityPopulations, City=Self.SelectedText.City))

5. Next, we are going to add a label, like before, with the Text property reading "Country:". Then select Input at the top and add a Text Input.

6. For the Default property of the Text Input, put varRecord.Country.

7. In the Tree View on the right-hand side, change the name of the input to txtCountry.

8. Repeat the previous 3 steps for City and Population now.

9. Select an option in the dropdown to see this in action.

10. Now, add a button to the screen and put it under the Population text input. Change the Text property to say "Submit".

11. Change the OnSelect property of the button to the following:

 Patch(CityPopulations, varRecord, {Country: txtCountry.Text, City: txtCity.Text, Population: Value(txtPopulation.Text)})


Note

We have to wrap txtPopulation.Text with Value() because the text input returns a string by default, and our collection expects a number.

12. Now change one of the values and find it in the gallery, you will see that it has changed.

1. Select our "Submit" button and copy it. Paste it three times.

2. Change the Text property of the three buttons to Clear, New, and Remove.

3. Ctrl-Click the Clear and Remove buttons. Change the DisplayMode property to:

 If(IsBlank(varRecord), DisplayMode.Disabled, DisplayMode.Edit)


Now these buttons will only be clickable if we have a record selected.

4. Ctrl-click the Remove button to deselect it. On the OnSelect property of the Clear button, put:

 Set(varRecord, Blank())


You can now clear the selected record using this button.

5. Select the Remove button now. On the OnSelect property put:

 Remove(CityPopulations, varRecord)

6. Finally, select the New button and change the OnSelect property of the button to:

 Collect(CityPopulations, {Country: txtCountry.Text, City: txtCity.Text, Population: Value(txtPopulation.Text)})


You are now able to add a record to the collection using the previously created text inputs.

You now know how to work more extensively with tables in Power Apps.