2 Commits (ae22682f2abcb47ee4d4f124daa0a3ecd685b6f2)

Author	SHA1	Message	Date
Tom Lane	05e3d0ee86	Reimplementation of UNION/INTERSECT/EXCEPT. INTERSECT/EXCEPT now meet the ... SQL92 semantics, including support for ALL option. All three can be used in subqueries and views. DISTINCT and ORDER BY work now in views, too. This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT where the SELECT yields different datatypes than the INSERT needs. I did that by making UNION subqueries and SELECT in INSERT be treated like subselects-in-FROM, thereby allowing an extra level of targetlist where the datatype conversions can be inserted safely. INITDB NEEDED!	26 years ago
Tom Lane	3a94e789f5	Subselects in FROM clause, per ISO syntax: FROM (SELECT ...) [AS] alias. ... (Don't forget that an alias is required.) Views reimplemented as expanding to subselect-in-FROM. Grouping, aggregates, DISTINCT in views actually work now (he says optimistically). No UNION support in subselects/views yet, but I have some ideas about that. Rule-related permissions checking moved out of rewriter and into executor. INITDB REQUIRED!	26 years ago