Thank you so much, did you mean the section 8.15.6??
------------------ Original message ------------------ From: "David G. Johnston"; Sendtime: Wednesday, May 23, 2018 9:18 PM To: "a"<372660...@qq.com>; Cc: "amul sul"; "pgsql-general"; Subject: How do I copy an element of composite type array into csv file? On Wednesday, May 23, 2018, a <372660...@qq.com> wrote: Thank you very much. BTW, may I ask if I would like to do the opposite that copy csv file content into the first element, how should I do it?? COPY B(Ay[1]) from 'E:/products_199.csv' DELIMITER ',' CSV HEADER; you cannot put "[1]" there. The csv file value has to be an array input literal with only one element. i.e., something like: {(1,2)} There is no first element as such when you are creating a new record. There will be however many elelements to supply to the array input. David J.