[HACKERS] "unexpected" query behaviour after i change parser code
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From: Mohammad Heykal Abdillah on 22 May 2010 09:21 All, Lately i have play with "parser"-part. I was try to make valid query command without using "FROM clause", so far it's work. I know this modification will make all query that using "FROM clause" failed, for example "/df" command. But normal or simple "select statement" so far is work. Now before my question, this what i do to make query without FROM clause work : 1) change "src/backend/parser/gram.y" at "simple_select:" delete from_clause 2) change "src/backend/parser/parse_relation.c" at function warnAutoRange, comment or delete "if (!add_missing_from)" part and change the "else" above to "if (add_missing_from)". Ok this my test result to "customer" and "item" table : - select id_item,name from item; --> failed, because there is "from clause" (failed like i expected) - select item.id_item, item.name; --> work, like i expected - select id_item,name; --> failed, with error : column "id_item" does not exist (failed like i expected) - select item.id_item,customer.fname; --> work, the data not acurate though because there is no joined atribut - select item.id_item,customer.fname where item.id_item=customer.id; --> work, normaly - select item.id,item; --> work, the result was concanted in "item" column. (i expected this query was failed). Try many combination including using more than one table with previous test, the result always work ONLY IF i put "table_name.colId" first. My question : 1) Can someone explain why my last test it's work? 2) Why PostgreSQL won't query my 3rd test? Considering my last test it's work. Thank You. *) Btw if you try my modification make sure you already have the data. I havent try any command yet, but i assume SET, or CREATE will failed. -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |