On 5/30/23 07:38, Adrian Klaver wrote:
On 5/30/23 06:45, Marc Millas wrote:
Hi,
I always have had difficulties to understand syntax. So...
If I have:
create table t1 (t text);
create table t2 (a text, b text, c test, d numeric);
Is c supposed to be text?
Or are you indeed referring to some unspecified type?
insert into t1('azerty');
INSERT 0 1
fine !
Not with that syntax:
insert into t1('azerty');
ERROR: syntax error at or near "'azerty'"
LINE 1: insert into t1('azerty');
insert into t1 values('azerty');
INSERT 0 1
so, now, if I write:
Select distinct test1.t, 'abc' as b, NULL as c, NULL as d
From t1 test1;
t | b | c | d
--------+-----+---+---
azerty | abc | |
(1 row)
ok.
Yes
and , now, if I want to insert that:
Insert into t2 (a, b, c, d)
Select distinct test1.t, 'abc' as b, NULL as c, NULL as d
From t1 test1;
I get:
ERROR: column "d" is of type numeric but expression is of type text
LINE 2: Select distinct test1.t, 'abc' as b, NULL as c, NULL as d
HINT: You will need to rewrite or cast the expression.
Can someone give a short SQL syntax hint ?
The hint is that though NULL is unknown it can have a type.
To get this to work I first did:
create table t2 (a text, b text, c text, d numeric);
to have c be text for simplicity sake.
Then I did:
Insert into t2 (a, b, c, d)
Select distinct test1.t, 'abc' as b, NULL::test, NULL::numeric
From t1 test1;
The above should have been:
Insert into t2 (a, b, c, d)
Select distinct test1.t, 'abc' as b, NULL::text, NULL::numeric
From t1 test1;
which results in:
select * from t2;
a | b | c | d
--------+-----+------+------
azerty | abc | NULL | NULL
thanks,
Marc MILLAS
Senior Architect
+33607850334
www.mokadb.com <http://www.mokadb.com>
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
