zeroifnull function
Applies to: 
Databricks Runtime 16.0 and later
Returns 0 if expr is NULL, or expr otherwise. This function is a synonym for coalesce(expr, 0).
Syntax
zeroifnull(expr)
Arguments
expr: A numeric expression.
Returns
The result type is the same as the type of expr.
Examples
> SELECT zeroifnull(0);
0
> SELECT zeroifnull(NULL);
0
> SELECT zeroifnull(5);
5