Utility functions
This section is to provide an overview of specific functions that are difficult to categorize, but are broadly useful.
| Function | Description | Example | Result |
|---|---|---|---|
coalesce(arg1, arg2) | returns the first non-NULL value from the list of elements | coalesce(NULL, 'a', NULL) | 'a' |
ifnull(arg1, arg2) | a two-argument version of coalesce | ifnull(NULL, 'a') | 'a' |
nullif(arg1, arg2) | if arg1 = arg2 return null, otherwise return arg1 | nullif('hello', 'world') | 'hello' |
constant_or_null(arg1, arg2) | if arg2 is null return null, otherwise return arg1 | constant_or_null(1, NULL) | NULL |
count_if(arg) | if arg is true or non-zero number return 1, other wise return 0 | count_if(true) | 1 |
typeof(arg) | return name of the data type of arg | typeof(true) | BOOL |
error(arg) | throw arg as a Runtime exception | error('something is wrong.') |