isnull
The isnull function evaluates its sole argument and returns a bool value indicating whether the argument evaluates to a null value.
Syntax
isnull( [ Expression ] )
Results
True or false, depending on whether the value is or is not null.
string values cannot be null. Use isempty to determine whether a value of type string is empty.
| x | isnull(x) |
|---|---|
| "" | false |
| “x” | false |
| parse_json("") | true |
| parse_json("[]") | false |
| parse_json("{}") | false |
Example
This example returns true:
print isnull( parse_json("No JSON here") )