On Thu, Jul 21, 2005 at 10:09:07PM -0700, Benjamin Smith wrote: > select classroom.title, > count(students.id) AS students, > count(seats.id) AS seats > from classrooms, students, seats > where classrooms.id=students.classrooms_id > and classrooms.id=seats.id > > Except that it counts 0s for seats/students. > > Why can't I recall/find how to do this particular join?
Sounds like you're looking for an outer join. http://www.postgresql.org/docs/8.0/static/tutorial-join.html http://www.postgresql.org/docs/8.0/static/queries-table-expressions.html#QUERIES-FROM -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---------------------------(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
