array_distinct function
Applies to: 
Databricks SQL Databricks Runtime
Removes duplicate values from array.
Syntax
array_distinct(array)
Arguments
array: An ARRAY expression.
Returns
The function returns an array of the same type as the input argument where all duplicate values have been removed.
Examples
SQL
> SELECT array_distinct(array(1, 2, 3, NULL, 3));
[1,2,3,NULL]