How to toggle a boolean field by sql in postgresql?

There is a field show which is a boolean type in postgesql.

I want to write a sql to update that table, to toggle the value of show. If it's true, it becomes false, if it's false, it becomes true.

Is it possible?

This will do:

SET show = NOT show

so a value of

TRUE becomes FALSE,

FALSE becomes TRUE,

UNKNOWN (NULL) stays UNKNOWN.

StackExchange Database Administrators Q#15768, answer score: 27