Hi
> -----Original Message-----
> From: a [mailto:372660931@qq.com]
> Sent: Mittwoch, 23. Mai 2018 11:43
> To: pgsql-general <pgsql-general@postgresql.org>
> Subject: How do I select composite array element that satisfy specific conditions.
>
> Hi, say if I have composite type and table
>
> create type A as(
> x float8,
> y float8
> );
>
> create table B(
> Ay A[]
> );
>
> insert into B
> values(array[
> (1,2)::A,
> (3,4)::A]
> );
>
> How could I select the element of Ay that satisfy x=3??
>
> Thank you so much!!
>
> Shore
I did not really follow this thread, so I am not in clear, why you want to complicate your life that much.
You create a custom data type and then use it in an array in a column. A complex hierarchical structure.
Why don't you simply use JSON or JSONB? Your example sounds terribly academic very much like a school assignment.
Bye
Charles