Cast struct column to array

Hi All,

I want to make this transformation :

columnA, columnB, columnC

to

Struct {columnA:"",columnB:"", columnC:""}

to

Array [{columnA:"",columnB:"", columnC:""}]

The first two step works, but I don't know how to transform from step 2 to 3, i.e struct to array

Someone got a solution ?

thanks in advance !