если stationcode
возвращает только одну строку, то вы можете попробовать это:
SELECT `stationcode`, PKG_R, WT_R, ERNG_R, PKG_P, WT_P, ERNG_P, PKG_S, WT_S, ERNG_S, PKG_L, WT_L, ERNG_L , SUM(PKG_R+PKG_P+PKG_S+PKG_L) AS TOTAL_PKGS
FROM
(
(Select sum(pis.NOPKGS) AS PKG_R from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') a,
(Select sum(pis.WTQTLS) AS WT_R from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') b,
(Select sum(pis.ERNGS) AS ERNG_R from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') c,
(Select sum(pis.NOPKGS) AS PKG_P from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') d,
(Select sum(pis.WTQTLS) AS WT_P from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') e,
(Select sum(pis.ERNGS) AS ERNG_P from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') f,
(Select sum(pis.NOPKGS) AS PKG_S from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') g,
(Select sum(pis.WTQTLS) AS WT_S from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') h,
(Select sum(pis.ERNGS) AS ERNG_S from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') i,
(Select sum(pis.NOPKGS) AS PKG_L from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') j,
(Select sum(pis.WTQTLS) AS WT_L from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') k,
(Select sum(pis.ERNGS) AS ERNG_L from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') l,
`station`
)
WHERE Parcels = 'TRUE'