Function is_boolean

The function checks a string variable for containing valid BOOLEAN values.

boolean strings
t
f
T
F
y
n
Y
N
true
false
TRUE
FALSE
yes
no
YES
NO
0
1

Examples

SELECT is_boolean('t') AS res;
-- Result is true

Result:

res
t

SELECT is_boolean('F') AS res;
-- Result is true

Result:

res
t

SELECT is_boolean('True') AS res;
-- Result is true

Result:

res
t

SELECT is_boolean('False');
-- Result is true

Result:

res
t

SELECT is_boolean('0') AS res;
-- Result is true

Result:

res
t

SELECT is_boolean('1') AS res;
-- Result is true

Result:

res
t

SELECT is_boolean('-1') AS res;
-- Result is false

Result:

res
f