On 9/18/07, Philippe Lang <[EMAIL PROTECTED]> wrote: > ... into this: > > > serial dateL dateR > -------------------- > 1 1 2 > 1 4 > 2 1 2 > 3 1 3 > 4 2 3 > 5 3
SELECT t1.serial, t1.DATE AS datel, t2.DATE AS dater FROM t t1 LEFT JOIN t t2 ON( t1.serial = t2.serial AND t1.DATE < t2.DATE) WHERE t1.delivery = 'L' AND ( t2.delivery = 'R' OR t2.delivery IS NULL) ORDER BY t1.serial ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org