postgres/contrib/file_fdw/data/text.csv

AAA,aaa,123,""
XYZ,xyz,"",321
NULL,NULL,NULL,NULL
NULL,NULL,"NULL",NULL
ABC,abc,"",""
Provide a FORCE NULL option to COPY in CSV mode. This forces an input field containing the quoted null string to be returned as a NULL. Without this option, only unquoted null strings behave this way. This helps where some CSV producers insist on quoting every field, whether or not it is needed. The option takes a list of fields, and only applies to those columns. There is an equivalent column-level option added to file_fdw. Ian Barwick, with some tweaking by Andrew Dunstan, reviewed by Payal Singh. 2014-03-04 17:31:59 -05:00			`AAA,aaa,123,""`
			`XYZ,xyz,"",321`
			`NULL,NULL,NULL,NULL`
			`NULL,NULL,"NULL",NULL`
			`ABC,abc,"",""`