Inserting array values - arrays

Question

How do I write and execute a query which inserts array values using libpqxx?
INSERT INTO exampleTable(exampleArray[3]) VALUES('{1, 2, 3}');
This example code gives me:
ERROR: syntax error at or near "'"
What is wrong? In PostgreSQL documentation I found that:
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"}}');

Answer 1

You should use a column name without an index to insert an array:
create table example(arr smallint[]);
insert into example(arr) values('{1, 2, 3}');
-- alternative syntax
-- insert into example(arr) values(array[1, 2, 3]);
select * from example;
arr
---------
{1,2,3}
(1 row)
Use the column name with an index to access a single element of the array:
select arr[2] as "arr[2]"
from example;
arr[2]
--------
2
(1 row)
update example set arr[2] = 10;
select * from example;
arr
----------
{1,10,3}
(1 row)
You can use arr[n] in INSERT but this has special meaning. With this syntax you can create an array with one element indexed from the given number:
delete from example;
insert into example(arr[3]) values (1);
select * from example;
arr
-----------
[3:3]={1}
(1 row)
As a result you have an array which lower bound is 3:
select arr[3] from example;
arr
-----
1
(1 row)

Answer 2

ref: https://ubiq.co/database-blog/how-to-insert-into-array-in-postgresql/
A. use ARRAY
insert into employees (id, name, phone_numbers)
values (1, ' John Doe', ARRAY ['9998765432','9991234567']);
// less nested quotes
B. use '{}'
insert into employees (id, name, phone_numbers)
values (2, ' Jim Doe', '{"9996587432","9891334567"}');
OR
insert into employees (id, name, phone_numbers)
values (2, ' Jim Doe', '{9996587432,9891334567}');
// seems inner quotes " not necessary,
// number or string depends on column type.