mysql - 子查询值的总和

Question

SELECT `stationcode`, 
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS PKG_R, (Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS WT_R,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS ERNG_R,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS PKG_P, (Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS WT_P,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS ERNG_P,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS PKG_S, (Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS WT_S,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS ERNG_S,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS PKG_L, (Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS WT_L,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS ERNG_L
,SUM(PKG_R+PKG_P+PKG_S+PKG_L) AS TOTAL_PKGS
FROM `station` WHERE Parcels = 'TRUE' 

上面的查询显示了这个错误:

Unknown column 'PKG_R' in 'field list'

Answer 1

您不能在单个查询中直接使用别名。您只能在外部使用这些别名，如下所示。

   SELECT stationcode,SUM(PKG_R+PKG_P+PKG_S+PKG_L) AS TOTAL_PKGS FROM (SELECT stationcode, 
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS PKG_R, 
(Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS WT_R,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE R') AS ERNG_R,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS PKG_P, 
(Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS WT_P,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE P') AS ERNG_P,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS PKG_S, 
(Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS WT_S,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE S') AS ERNG_S,
(Select sum(pis.NOPKGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS PKG_L, 
(Select sum(pis.WTQTLS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS WT_L,
(Select sum(pis.ERNGS) from pis where pis.prcldate = '2018-11-28' and pis.parcelstn = station.stationcode and pis.BKDSCALE = 'SCALE L') AS ERNG_L
FROM station WHERE Parcels = 'TRUE' ) A
GROUP BY stationcode