> I try to convert code from other database to Postgres. > > CREATE TABLE test(test BOOLEAN); > SELECT MAX(test) FROM test; > > causes error > > ERROR: function max(boolean) does not exist > HINT: No function matches the given name and argument types. You may need > to add explicit type casts. > > I tried > SELECT MAX(test:integer)::boolean FROM test; > > but this casuses error > > ERROR: cannot cast type boolean to integer > > I have lot of MAX() functions applied to boolean expressions. > > How to force Postgres to calculate MAX(boolean) ? > > MAX(boolean) should return true if its argument evaluates true for at least > one row. > Have you looked into creating a suitable aggregate function yourself? \h CREATE AGGREGATE http://www.postgresql.org/docs/current/static/xaggr.html -- output = reverse("gro.gultn" "@" "enworbbc") http://linuxdatabases.info/info/rdbms.html "The test of a principle is whether it applies even to people you don't like." -- Henry Spencer ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
