Thank you - this has worked:
COPY words_reviews (uid, author, nice, review, updated) FROM stdin WITH (FORMAT csv);
1,2,1,'1 is nice by 2','2017-03-01'
1,3,1,'1 is nice by 3','2017-03-02'
1,4,1,'1 is nice by 4','2017-03-03'
2,1,1,'2 is nice by 1','2017-03-01'
2,3,1,'2 is nice by 3','2017-03-02'
2,4,0,'2 is not nice by 4','2017-03-03'
\.
but I am confused about the comments that I should use \copy and not just COPY and also that I could leave out WITH and brackets.
Because please take a look at the 9.6.2 psql output (COPY works, and leaving out WITH brackets - not):
words=> COPY words_reviews (uid, author, nice, review, updated) FROM stdin WITH (FORMAT csv);
Enter data to be copied followed by a newline.
End with a backslash and a period on a line by itself.
>> 1,2,1,'1 is nice by 2','2017-03-01'
1,3,1,'1 is nice by 3','2017-03-02'
1,4,1,'1 is nice by 4','2017-03-03'
2,1,1,'2 is nice by 1','2017-03-01'
2,3,1,'2 is nice by 3','2017-03-02'
2,4,0,'2 is not nice by 4','2017-03-03'
\.
>> >> >> >> >> >> COPY 6
words=> COPY words_reviews (uid, author, nice, review, updated) FROM stdin FORMAT csv;
ERROR: syntax error at or near "FORMAT"
LINE 1: ...s (uid, author, nice, review, updated) FROM stdin FORMAT csv...
^
