array_append function
Applies to: 
Databricks SQL Databricks Runtime 12.2 LTS and above
Returns array appended by elem.
Syntax
array_append(array, elem)
Arguments
array: An ARRAY.elem: An expression of the same type as the elements ofarray.
Returns
An ARRAY of the same type as array.
Examples
SQL
> SELECT array_append(array(1, 2, 3), 0);
[1,2,3,0]
> SELECT array_append(array(1, 2, 3), NULL);
[1,2,3,NULL]