Self join Quiz

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SELF JOIN quiz

1. Select the code that would show it is possible to get from Craiglockhart to Haymarket

SELECT DISTINCT a.name, b.name from stops a JOIN route z IN a.id=z.stop JOIN route y ON y.num = z.num JOIN stops b IN y.stop=b.id where a.name='Craiglockhart' AND b.name ='Haymarket'
SELECT DISTINCT a.name, b.name from stops a JOIN route z ON a.id=z.stop JOIN route y JOIN stops b ON y.stop=b.id where a.name='Craiglockhart' AND b.name ='Haymarket'
SELECT DISTINCT a.name, b.name from stops a JOIN route z ON a.id=z.stop JOIN route y ON y.num = z.num JOIN stops b ON y.stop=b.id where a.name='Craiglockhart' AND b.name ='Haymarket'
SELECT DISTINCT a.name, b.name from stops a JOIN route z ON a.id=z.stop JOIN route y ON y.num = z.num JOIN stops b ON y.stop=b.id where a.name='Craiglockhart' AND b.name ='Sighthill'
SELECT DISTINCT a.name, b.name from stops a JOIN route z ON a.id=z.stop JOIN route y ON y.num = z.num JOIN stops b ON y.stop=b.id where y.name='Craiglockhart' AND z.name ='Haymarket'

2. Select the code that shows the stops that are on route.num '2A' which can be reached with one bus from Haymarket?

SELECT S2.id, S2.name, R2.company, R2.num FROM stops S1, stops S2, route R1, route R2 WHERE S1.name='Haymarket' AND S1.id=R1.stop AND R1.company=R2.company AND R1.num=R2.num AND R2.stop=S2.id AND R2.num='2A'
SELECT S2.id, S2.name, R2.company, R2.num FROM stops S1, stops S2, route R1, route R2 WHERE S1.name='Craiglockhart' AND S1.id=R1.stop AND R1.company=R2.company AND R1.num=R2.num AND R2.stop=S2.id AND R2.num='2A'
SELECT S2.id, S2.name, R2.company, R2.num FROM stops S1, stops S2, route R1, route R2 WHERE S1.name='Haymarket' AND S1.id=R1.stop AND R1.company=R2.company AND R1.num=R2.num AND R2.stop=S2.id
SELECT S2.id, S2.name, R2.company, R2.num FROM stops S1, stops S2, route R1, route R2 WHERE S1.name='Haymarket' AND S1.id=R1.stop AND R1.company=R2.company AND R1.num=R2.num AND R2.stop=S2.id AND R2.num='2'
SELECT S2.id, S2.name, R2.company, R2.num FROM stops S1, stops S2, route R1, route R2 WHERE S1.name='Haymarket' AND S1.id=R1.stop AND R1.company=R2.company AND R1.num=R2.num AND R2.stop=S2.id AND R2.num='2A'

3. Select the code that shows the services available from Tollcross?

SELECT a.company, a.num, stopa.name, stopb.name FROM route a JOIN route b ON (a.company=b.company AND a.num=b.num) JOIN stops stopa ON (a.stop=stopa.id) JOIN stops stopb ON (b.stop=stopb.id)
SELECT a.company, a.num, stopa.name, stopb.name FROM route a JOIN route b ON (a.company=b.company AND a.num=b.num) JOIN stops stopa ON (a.stop=stopa.id) JOIN stops stopb ON (b.stop=stopb.id) WHERE stopa.name='Sighthill'
SELECT a.company, a.num, stopa.name, stopb.name FROM route a JOIN route b IN (a.company=b.company AND a.num=b.num) JOIN stops stopa IN (a.stop=stopa.id) JOIN stops stopb ON (b.stop=stopb.id) WHERE stopa.name='Tollcross'
SELECT a.company, a.num, stopa.name, stopb.name FROM route a JOIN route b ON (a.company=b.company AND a.num=b.num) JOIN stops stopa ON (a.stop=stopa.id) JOIN stops stopb ON (b.stop=stopb.id) WHERE stopa.name='Tollcross'
SELECT a.company, a.num, stopa.name, stopb.name FROM route a JOIN route b ON (a.company=b.company AND a.num=b.num) JOIN stops stopa ON (a.stop=stopa.id) JOIN stops stopb ON (b.stop=stopb.id) WHERE stopz.name='Tollcross'

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