Hi all, I tried to work with NULL items in an array but there are two things I don't understand. (I just did a cvs update, make, make install... so sources are current.)
On http://momjian.us/main/writings/pgsql/sgml/arrays.html, you can read : To set an element of an array constant to NULL, write NULL for the element value. (Any upper- or lower-case variant of NULL will do.) If you want an actual string value "NULL", you must put double quotes around it. amarok=# SELECT ARRAY['a',NULL,'c']; array ------------ {a,NULL,c} (1 row) Setting a NULL value seems to work. amarok=# SELECT ARRAY['a',"NULL",'c']; ERROR: column "NULL" does not exist LINE 1: SELECT ARRAY['a',"NULL",'c']; ^ Using double quotes throws an error. amarok=# SELECT ARRAY['a','NULL','c']; array -------------- {a,"NULL",c} (1 row) Using single quotes seems to work. Is it a documentation mistake ? Or did I miss something ? There's another thing I don't understand. What is the use for array_nulls configuration variable ? amarok=# SET array_nulls TO off; SET amarok=# SELECT ARRAY['a','NULL','c']; array -------------- {a,"NULL",c} (1 row) amarok=# SELECT ARRAY['a',"NULL",'c']; ERROR: column "NULL" does not exist LINE 1: SELECT ARRAY['a',"NULL",'c']; ^ amarok=# SELECT ARRAY['a',NULL,'c']; array ------------ {a,NULL,c} (1 row) Disabling it doesn't seem to have any effect at all in the way PostgreSQL treats NULL values. I thought SELECT ARRAY['a',NULL,'c'] would behave like SELECT ARRAY['a','NULL','c'] with array_nulls disabled. Did I misunderstand something ? I would be really interested in any information or documentation you can give me on these matters. Thanks. Regards. -- Guillaume. <!-- http://abs.traduc.org/ http://lfs.traduc.org/ http://docs.postgresqlfr.org/ --> ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
