Modifying Arrays
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/15/arrays.html
Description:
According to the official document of PostgreSQL 15, in the section 8.15.4.
Modifying Arrays there is a statement like:
The slice syntaxes with omitted lower-bound and/or upper-bound can be used
too, but only when updating an array value that is not NULL or
zero-dimensional (otherwise, there is no existing subscript limit to
substitute).
This statement is not true for the following statements or I am missing
something?
CREATE TABLE sal_emp (
name text,
pay_by_quarter integer[],
schedule text[][]
);
INSERT INTO sal_emp
VALUES ('Bill',
'{10000, 10000, 10000, 10000}',
'{{"meeting", "lunch"}, {"training", "presentation"}}');
INSERT INTO sal_emp
VALUES ('Carol',
'{20000, 25000, 25000, 25000}',
'{{"breakfast", "consulting"}, {"meeting", "lunch"}}');
INSERT INTO sal_emp
VALUES ('Carolx',
'{20000, 25001, 25002, 25003}',
'{{"breakfastx", "consultingx"}, {"meetingx", "lunchx"}, {"meetingy",
"lunchy"}}');
INSERT INTO sal_emp
VALUES ('Sam',
'{20000, 25001, 25002, 25003}',
'{}');
INSERT INTO sal_emp
VALUES ('Pam',
'{20000, 25001, 25002, 25003}');
SELECT * FROM sal_emp;
UPDATE sal_emp SET schedule[1:2] = '{"asd", "asa"}'
WHERE name = 'Sam';
UPDATE sal_emp SET schedule[1:2] = '{"x", "y"}'
WHERE name = 'Pam';
SELECT * FROM sal_emp;
In order to test it: https://dbfiddle.uk/pHKY32u0
Thanks!
PG Doc comments form <noreply@postgresql.org> writes:
According to the official document of PostgreSQL 15, in the section 8.15.4.
Modifying Arrays there is a statement like:
The slice syntaxes with omitted lower-bound and/or upper-bound can be used
too, but only when updating an array value that is not NULL or
zero-dimensional (otherwise, there is no existing subscript limit to
substitute).
This statement is not true for the following statements or I am missing
something?
Your example doesn't use a slice with omitted bound, so I'm not quite sure
what you are trying to show? Using your test data, a slice with omitted
bound does fail with Pam's null schedule:
=> UPDATE sal_emp SET schedule[:2] = '{"w", "x", "y", "z"}' WHERE name = 'Pam';
ERROR: array slice subscript must provide both boundaries
DETAIL: When assigning to a slice of an empty array value, slice boundaries must be fully specified.
but it works for the other entries:
=> UPDATE sal_emp SET schedule[:2] = '{"w", "x", "y", "z"}' WHERE name != 'Pam';
UPDATE 3
=> table sal_emp;
name | pay_by_quarter | schedule
--------+---------------------------+---------------------------------
Pam | {20000,25001,25002,25003} |
Bill | {10000,10000,10000,10000} | {{w,x},{y,z}}
Carol | {20000,25000,25000,25000} | {{w,x},{y,z}}
Carolx | {20000,25001,25002,25003} | {{w,x},{y,z},{meetingy,lunchy}}
(4 rows)
regards, tom lane
Hi Tom,
Thanks for the e - mail. I did interpret it exactly in a different manner,
it was my mistake. I am sorry.
Thanks!
On Mon, Feb 27, 2023 at 4:41 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Show quoted text
PG Doc comments form <noreply@postgresql.org> writes:
According to the official document of PostgreSQL 15, in the section
8.15.4.
Modifying Arrays there is a statement like:
The slice syntaxes with omitted lower-bound and/or upper-bound can be
used
too, but only when updating an array value that is not NULL or
zero-dimensional (otherwise, there is no existing subscript limit to
substitute).This statement is not true for the following statements or I am missing
something?Your example doesn't use a slice with omitted bound, so I'm not quite sure
what you are trying to show? Using your test data, a slice with omitted
bound does fail with Pam's null schedule:=> UPDATE sal_emp SET schedule[:2] = '{"w", "x", "y", "z"}' WHERE name =
'Pam';
ERROR: array slice subscript must provide both boundaries
DETAIL: When assigning to a slice of an empty array value, slice
boundaries must be fully specified.but it works for the other entries:
=> UPDATE sal_emp SET schedule[:2] = '{"w", "x", "y", "z"}' WHERE name !=
'Pam';
UPDATE 3
=> table sal_emp;
name | pay_by_quarter | schedule
--------+---------------------------+---------------------------------
Pam | {20000,25001,25002,25003} |
Bill | {10000,10000,10000,10000} | {{w,x},{y,z}}
Carol | {20000,25000,25000,25000} | {{w,x},{y,z}}
Carolx | {20000,25001,25002,25003} | {{w,x},{y,z},{meetingy,lunchy}}
(4 rows)regards, tom lane