我正在努力加入别名命名列。总的来说,我想要一个带有日期,小时,以及实际和预测的输出(最近一天早上10点前)风速。加入别名列SQL
有了下面的代码我得到:
ERROR: column "date" does not exist
LINE xx: ...ast_prep.lat AND meso.lon = forecast_prep.lon AND Date ...
我无法弄清楚如何让SQL加入这些命名的列。
谢谢。是的,我是一个SQL新手。
with forecast_prep as (
SELECT
date_trunc('day', foretime)::date AS Foredate,
extract(hour from foretime)+1 AS foreHE,
lat,
lon,
windspeed,
max(as_of) AS as_of
FROM weather.forecast
WHERE date_trunc('day', foretime)::date-as_of>= interval '16 hours'
GROUP BY Foredate, foreHE, lat, lon, windspeed)
SELECT
meso.station,
date_trunc('day', meso.timestmp)::date AS Date,
extract(hour from meso.timestmp)+1 AS HE,
CAST(AVG(meso.windspd) as numeric(19,2)) As Actual,
forecast_prep.windspeed,
forecast_prep.as_of
FROM weather.meso
INNER JOIN forecast_prep ON (
meso.lat = forecast_prep.lat AND
meso.lon = forecast_prep.lon AND
Date = Foredate AND ----<<<< Error here
HE = foreHE)
WHERE
(meso.timestmp Between '2016-02-01' And '2016-02-02') AND
(meso.station='KSBN')
GROUP BY meso.station, Date, HE, forecast_prep.windspeed, forecast_prep.as_of
ORDER BY Date, HE ASC
下面是表的结构:
-- Table: weather.forecast
-- DROP TABLE weather.forecast;
CREATE TABLE weather.forecast
(
foretime timestamp without time zone NOT NULL,
as_of timestamp without time zone NOT NULL, -- in UTC
summary text,
precipintensity numeric(8,4),
precipprob numeric(2,2),
temperature numeric(5,2),
apptemp numeric(5,2),
dewpoint numeric(5,2),
humidity numeric(2,2),
windspeed numeric(5,2),
windbearing numeric(4,1),
visibility numeric(5,2),
cloudcover numeric(4,2),
pressure numeric(6,2),
ozone numeric(5,2),
preciptype text,
lat numeric(8,6) NOT NULL,
lon numeric(9,6) NOT NULL,
CONSTRAINT forecast_pkey PRIMARY KEY (foretime, as_of, lat, lon)
-- Table: weather.meso
-- DROP TABLE weather.meso;
CREATE TABLE weather.meso
(
timestmp timestamp without time zone NOT NULL,
station text NOT NULL,
lat numeric NOT NULL,
lon numeric NOT NULL,
tmp numeric,
hum numeric,
windspd numeric,
winddir integer,
dew numeric,
CONSTRAINT meso_pkey PRIMARY KEY (timestmp, station, lat, lon)
为什么MySQL的标签? – Strawberry
错误修复。 @Strawberry – otterdog2000
'... date_trunc('day',meso.timestmp):: date = Foredate AND ...'?除了'group'和'order'子句外,不可能使用列的别名。 – Abelisto