map_filter function
Applies to: 
Databricks SQL Databricks Runtime
Filters entries in the map in expr using the function func.
Syntax
map_filter(expr, func)
Arguments
expr: A MAP expression.func: A lambda function with two parameters returning a BOOLEAN. The first parameter takes the key the second parameter takes the value.
Returns
The result is the same type as expr.
Examples
SQL
> SELECT map_filter(map(1, 0, 2, 2, 3, -1), (k, v) -> k > v);
{1 -> 0, 3 -> -1}