### Database Schema:
CREATE TABLE relation (
	store_nbr	INTEGER	NULL	PRIMARY KEY,
	station_nbr	INTEGER	NULL,
	foreign key (store_nbr) references sales_in_weather (store_nbr),
	foreign key (station_nbr) references weather (station_nbr)
);

CREATE TABLE weather (
	station_nbr	INTEGER	NULL	PRIMARY KEY,
	date	DATE	NULL	PRIMARY KEY,
	tmax	INTEGER	NULL,
	tmin	INTEGER	NULL,
	tavg	INTEGER	NULL,
	depart	INTEGER	NULL,
	dewpoint	INTEGER	NULL,
	wetbulb	INTEGER	NULL,
	heat	INTEGER	NULL,
	cool	INTEGER	NULL,
	sunrise	TEXT	NULL,
	sunset	TEXT	NULL,
	codesum	TEXT	NULL,
	snowfall	REAL	NULL,
	preciptotal	REAL	NULL,
	stnpressure	REAL	NULL,
	sealevel	REAL	NULL,
	resultspeed	REAL	NULL,
	resultdir	INTEGER	NULL,
	avgspeed	REAL	NULL
);

CREATE TABLE sales_in_weather (
	date	DATE	NULL	PRIMARY KEY,
	store_nbr	INTEGER	NULL	PRIMARY KEY,
	item_nbr	INTEGER	NULL	PRIMARY KEY,
	units	INTEGER	NULL
);

### User's Query:
Among the stores in weather station 14 in February 2014, which store had sold no less than 300 quantities for item number 44 in a single day?

### Extra Knowledge:
weather station 14 refers to station_nbr = 14; February 2014 refers to substring (date, 1, 7) = '2014-02' ; sold no less than 300 quantities refers to units > = 300; item no.44 refers to item_nbr = 44; store refers to store_nbr
SELECT T1.store_nbr FROM sales_in_weather AS T1 INNER JOIN relation AS T2 ON T1.store_nbr = T2.store_nbr WHERE T2.station_nbr = 14 AND T1.`date` LIKE '%2014-02%' AND T1.item_nbr = 44 AND units >= 300