Gavin Sherry <[EMAIL PROTECTED]> writes: > I haven't had time to look into it further, but it occurs to me that > handling views which rely on joins would be far from trivial.
Views containing joins would not be updatable; problem solved. The set of views the automatic-rule-generation machinery needs to handle are those defined as updatable by the SQL spec. SQL92 says 12)A <query specification> QS is updatable if and only if the fol- lowing conditions hold: a) QS does not specify DISTINCT. b) Every <value expression> contained in the <select list> imme- diately contained in QS consists of a <column reference>, and no <column reference> appears more than once. c) The <from clause> immediately contained in the <table ex- pression> immediately contained in QS specifies exactly one <table reference> and that <table reference> refers either to a base table or to an updatable derived table. Note: updatable derived table is defined in Subclause 6.3, "<table reference>". d) If the <table expression> immediately contained in QS imme- diately contains a <where clause> WC, then no leaf generally underlying table of QS shall be a generally underlying table of any <query expression> contained in WC. e) The <table expression> immediately contained in QS does not include a <group by clause> or a <having clause>. The reference to 6.3 appears to be pointing at this: 8) A <derived table> is an updatable derived table if and only if the <query expression> simply contained in the <subquery> of the <table subquery> of the <derived table> is updatable. I haven't quite wrapped my head around what clause 12d means, but 12c is perfectly clear that you only get one table reference. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html