Between 1/1/2012 to 12/31/2014, which date recorded the hottest temperature in weather station 1?
weather station 1 refers to station_nbr = 1; hottest temperature refers to Max(tmax); between 1/1/2012 to 12/31/2014 refers to SUBSTR(date, 1, 4) between 2012 and 2014
SELECT `date` FROM weather WHERE station_nbr = 1 AND CAST(SUBSTR(`date`, 1, 4) AS int) BETWEEN 2012 AND 2014 ORDER BY tmax DESC LIMIT 1
CREATE TABLE sales_in_weather
(
    date      DATE,
    store_nbr INTEGER,
    item_nbr  INTEGER,
    units     INTEGER,
    primary key (store_nbr, date, item_nbr)
);
CREATE TABLE weather
(
    station_nbr INTEGER,
    date        DATE,
    tmax        INTEGER,
    tmin        INTEGER,
    tavg        INTEGER,
    depart      INTEGER,
    dewpoint    INTEGER,
    wetbulb     INTEGER,
    heat        INTEGER,
    cool        INTEGER,
    sunrise     TEXT,
    sunset      TEXT,
    codesum     TEXT,
    snowfall    REAL,
    preciptotal REAL,
    stnpressure REAL,
    sealevel    REAL,
    resultspeed REAL,
    resultdir   INTEGER,
    avgspeed    REAL,
    primary key (station_nbr, date)
);
CREATE TABLE relation
(
    store_nbr   INTEGER
            primary key,
    station_nbr INTEGER,
    foreign key (store_nbr) references sales_in_weather(store_nbr),
    foreign key (station_nbr) references weather(station_nbr)
);
