Gå med i Alias ​​Columns SQL

"Date"-aliaset kan inte ses därifrån.

Du kan använda ett fåtal tabeller efter WITH, så jag råder dig att flytta andra valet dit.

Jag är inte helt säker på weather.mesos tabellstruktur men genom att gissa baserat på din fråga borde detta fungera:

WITH
    forecast_prep AS (
        SELECT
              date_trunc('day', foretime) :: DATE AS Foredate,
              extract(HOUR FROM foretime) + 1     AS foreHE,
              lat,
              lon,
              max(windspeed) as 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
   ),
   tmp AS (
      SELECT
        meso.station,
        meso.lat,
        meso.lon,
        meso.timestmp,
        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
      FROM weather.meso
      GROUP BY station, lat, lon, timestmp, Date, HE
   )
SELECT 
    tmp.station, tmp.Date, tmp.HE, tmp.Actual, forecast_prep.windspeed, forecast_prep.as_of
FROM tmp
INNER JOIN forecast_prep ON (
    tmp.lat = forecast_prep.lat 
    AND tmp.lon = forecast_prep.lon 
    AND tmp.Date = forecast_prep.Foredate
    AND tmp.HE = forecast_prep.foreHE
)
WHERE 
    (tmp.timestmp BETWEEN '2016-02-01' AND '2016-02-02') 
    AND (tmp.station = 'KSBN')
GROUP BY 
    tmp.station, tmp.Date, tmp.HE, forecast_prep.windspeed, forecast_prep.as_of, tmp.Actual
ORDER BY tmp.Date, tmp.HE ASC;

Som i det första exemplet här https://www.postgresql.org/docs/8.4/static/queries-with.html