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,


  • 1
    @a_horse_with_no_name: Yeah, but I had to write something to cover the 30 characters limitation. Since we already had TRUE and FALSE, a variation on UNKNOWN was appropriate :) – ypercubeᵀᴹ Mar 29 '12 at 6:38
  • This is awesome, elegant, and exactly what I wanted. Ultra glad this isn't only possible MySQL. – sudowned Sep 3 '12 at 4:15

The following will turn FALSE or NULL to TRUE, and TRUE to FALSE:

UPDATE tablename SET fieldname = NOT COALESCE( fieldname, 'f' ) WHERE keyvalue = ?;

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