On 04/08/2018 08:44 PM, Đỗ Ngọc Trí Cường wrote:
Dear Arian Klaver,
I think there is a misunderstood here.
I think that I quite understand how is the second query run.
The question I asked here is why exporting data, which is generated by a
query "JSON_AGG" , with command "COPY". The data contain "\n" as 2
characters instead of "new line" character.
https://www.postgresql.org/docs/10/static/sql-copy.html
File Formats
Text Format
"
\n Newline (ASCII 10)
Presently, COPY TO will never emit an octal or hex-digits backslash
sequence, but it does use the other sequences listed above for those
control characters.
...
COPY TO will terminate each row with a Unix-style newline (“\n”).
"
The second query is for the old version of PostgreSQL (9.3 and previous)
cause of they don't have JSON_AGG aggregate function. Since 9.4, we have
"JSON_AGG" already. So I want to rewrite and reduce the length of the
query. But it is don't work as I expected with command COPY.
Thank you and best regards,
Đỗ Ngọc Trí*Cường*(Mr.) | *Software Development Department*| +84 28 3715
5325
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx