On 1/24/19 5:04 AM, Alexandre GRAIL
wrote:
Hello
the list,
Maybe this question has been debated before (I didn't find
anything helpful) but :
Why the default is to throw an error when casting Integer to
Boolean in assignment, and accepting it everywhere else ?
So you can type :
postgres=# select 1::boolean;
bool
------
t
(1 row)
or
postgres=# select 0::boolean;
bool
------
f
(1 row)
But you *cannot* use 1 or 0 as valid input for boolean type when
inserting or updating :
test=# CREATE TABLE test1 (a boolean);
CREATE TABLE
test=# INSERT INTO test1 VALUES (1);
ERROR: column "a" is of type boolean but _expression_ is of type
integer
LINE 1: INSERT INTO test1 VALUES (1);
^
HINT: You will need to rewrite or cast the _expression_.
This behavior cannot be changed, as this cast is hard coded with
"Implicit?=no".
And added to this weirdness is the fact that '1' or '0' (with
quote) is OK.
So is there a reason to forbid 0 and 1 as valid boolean, without
explicit cast ?
I'm confused at the question. You are happily casting 1 and 0 to
boolean in the SELECT statements, and then grumbling when not
casting them in the INSERT statements. Thus, why aren't you casting
during the INSERT statements?
test=# INSERT INTO test1 VALUES (1::boolean);
--
Angular momentum makes the world go 'round.
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