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.
answered Mar 29 '12 at 6:32
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1@a_horse_with_no_name: Yeah, but I had to write something to cover the 30 characters limitation. Since we already had
TRUEandFALSE, a variation onUNKNOWNwas 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 = ?;
