Question

The coalesce function provides one way to substitute constant values for which values

Answer 1

“Coalesce function provides one way to replace with  constant values for null values”.

The COALESCE function test outs the value of each expression in the order in which they are listed and returns the initial non-null or non-missing value.

If only one value is mentioned, then the COALESCE function returns the value of that argument.