Hi @Rob_LVT :
Do you want to update multiple collections with multiple data sources through the check box in the gallery?
First of all, thanks for @WarrenBelz 's solution.
Secondly,my solution uses nested If and swith functions,I've made a test for your reference:
My data source:
'List A' (SharePoint List)
'List B'(SharePoint List)
'[dbo].[Table_2]'(SQL Sever Table)
1\Add a gallerycontrol
Items:
["List A","List B","[dbo].[Table_2]"] /*Use the table composed of data source names as the data source of the gallery*/
2\Add a check box control(Checkbox2) into this gallery
OnSelect:
If(
Checkbox2.Value, /*Determine the status of the current checkbox*/
Switch( /*Determine the currently selected record*/
ThisItem.Value,
"List A",
ClearCollect( /*Update collection,collection1/2/3 is my custom collection*/
collection1,
'List A'
),
"List B",
ClearCollect(
collection2,
'List B'
),
"[dbo].[Table_2]",
ClearCollect(
collection3,
'[dbo].[Table_2]'
)
), Switch( /*if Checkbox2.Value is false, then clear the specific collection*/
ThisItem.Value,
"List A",
Clear(
collection1
),
"List B",
Clear(
collection2
),
"[dbo].[Table_2]",
Clear(
collection3)
)
)

Best Regards,
Bof