SQL Exercise: Find the match in which Germany played against Poland
4. From the following tables, write a SQL query to find the match number in which Germany played against Poland. Group the result set on match number. Return match number.
Sample table: match_detailsmatch_no | play_stage | team_id | win_lose | decided_by | goal_score | penalty_score | ass_ref | player_gk ----------+------------+---------+----------+------------+------------+---------------+---------+----------- 1 | G | 1207 | W | N | 2 | | 80016 | 160140 1 | G | 1216 | L | N | 1 | | 80020 | 160348 2 | G | 1201 | L | N | 0 | | 80003 | 160001 2 | G | 1221 | W | N | 1 | | 80023 | 160463 3 | G | 1224 | W | N | 2 | | 80031 | 160532 3 | G | 1218 | L | N | 1 | | 80025 | 160392 4 | G | 1206 | D | N | 1 | | 80008 | 160117 4 | G | 1217 | D | N | 1 | | 80019 | 160369 5 | G | 1222 | L | N | 0 | | 80011 | 160486 5 | G | 1204 | W | N | 1 | | 80022 | 160071 6 | G | 1213 | W | N | 1 | | 80036 | 160279 6 | G | 1212 | L | N | 0 | | 80029 | 160256 7 | G | 1208 | W | N | 2 | | 80014 | 160163 7 | G | 1223 | L | N | 0 | | 80006 | 160508 8 | G | 1219 | W | N | 1 | | 80018 | 160416 8 | G | 1205 | L | N | 0 | | 80012 | 160093 9 | G | 1215 | D | N | 1 | | 80017 | 160324 9 | G | 1220 | D | N | 1 | | 80010 | 160439 10 | G | 1203 | L | N | 0 | | 80004 | 160047 10 | G | 1211 | W | N | 2 | | 80007 | 160231 11 | G | 1202 | L | N | 0 | | 80026 | 160024 11 | G | 1209 | W | N | 2 | | 80028 | 160187 12 | G | 1214 | D | N | 1 | | 80009 | 160302 12 | G | 1210 | D | N | 1 | | 80015 | 160208 13 | G | 1217 | L | N | 1 | | 80001 | 160369 13 | G | 1218 | W | N | 2 | | 80002 | 160392 14 | G | 1216 | D | N | 1 | | 80030 | 160348 14 | G | 1221 | D | N | 1 | | 80032 | 160463 15 | G | 1207 | W | N | 2 | | 80033 | 160140 15 | G | 1201 | L | N | 0 | | 80027 | 160001 16 | G | 1206 | W | N | 2 | | 80005 | 160117 16 | G | 1224 | L | N | 1 | | 80013 | 160531 17 | G | 1223 | L | N | 0 | | 80035 | 160508 17 | G | 1212 | W | N | 2 | | 80034 | 160256 18 | G | 1208 | D | N | 0 | | 80021 | 160163 18 | G | 1213 | D | N | 0 | | 80024 | 160278 19 | G | 1211 | W | N | 1 | | 80016 | 160231 19 | G | 1220 | L | N | 0 | | 80020 | 160439 20 | G | 1205 | D | N | 2 | | 80004 | 160093 20 | G | 1204 | D | N | 2 | | 80007 | 160071 21 | G | 1219 | W | N | 3 | | 80017 | 160416 21 | G | 1222 | L | N | 0 | | 80010 | 160486 22 | G | 1203 | W | N | 3 | | 80009 | 160047 22 | G | 1215 | L | N | 0 | | 80015 | 160324 23 | G | 1210 | D | N | 1 | | 80030 | 160208 23 | G | 1209 | D | N | 1 | | 80032 | 160187 24 | G | 1214 | D | N | 0 | | 80008 | 160302 24 | G | 1202 | D | N | 0 | | 80019 | 160024 25 | G | 1216 | L | N | 0 | | 80035 | 160348 25 | G | 1201 | W | N | 1 | | 80034 | 160001 26 | G | 1221 | D | N | 0 | | 80001 | 160463 26 | G | 1207 | D | N | 0 | | 80002 | 160140 27 | G | 1217 | L | N | 0 | | 80011 | 160369 27 | G | 1224 | W | N | 3 | | 80022 | 160531 28 | G | 1218 | D | N | 0 | | 80003 | 160392 28 | G | 1206 | D | N | 0 | | 80023 | 160117 29 | G | 1223 | L | N | 0 | | 80031 | 160508 29 | G | 1213 | W | N | 1 | | 80025 | 160278 30 | G | 1212 | L | N | 0 | | 80026 | 160256 30 | G | 1208 | W | N | 1 | | 80028 | 160163 31 | G | 1205 | L | N | 0 | | 80033 | 160093 31 | G | 1222 | W | N | 2 | | 80027 | 160486 32 | G | 1204 | W | N | 2 | | 80021 | 160071 32 | G | 1219 | L | N | 1 | | 80024 | 160416 33 | G | 1210 | W | N | 2 | | 80018 | 160208 33 | G | 1202 | L | N | 1 | | 80012 | 160024 34 | G | 1209 | D | N | 3 | | 80014 | 160187 34 | G | 1214 | D | N | 3 | | 80006 | 160302 35 | G | 1211 | L | N | 0 | | 80036 | 160233 35 | G | 1215 | W | N | 1 | | 80029 | 160324 36 | G | 1220 | L | N | 0 | | 80005 | 160439 36 | G | 1203 | W | N | 1 | | 80013 | 160047 37 | R | 1221 | L | P | 1 | 4 | 80004 | 160463 37 | R | 1213 | W | P | 1 | 5 | 80007 | 160278 38 | R | 1224 | W | N | 1 | | 80014 | 160531 38 | R | 1212 | L | N | 0 | | 80006 | 160256 39 | R | 1204 | L | N | 0 | | 80003 | 160071 39 | R | 1214 | W | N | 1 | | 80023 | 160302 40 | R | 1207 | W | N | 2 | | 80008 | 160140 40 | R | 1215 | L | N | 1 | | 80019 | 160324 41 | R | 1208 | W | N | 3 | | 80018 | 160163 41 | R | 1218 | L | N | 0 | | 80012 | 160392 42 | R | 1209 | L | N | 0 | | 80017 | 160187 42 | R | 1203 | W | N | 4 | | 80010 | 160047 43 | R | 1211 | W | N | 2 | | 80009 | 160231 43 | R | 1219 | L | N | 0 | | 80015 | 160416 44 | R | 1206 | L | N | 1 | | 80001 | 160117 44 | R | 1210 | W | N | 2 | | 80002 | 160208 45 | Q | 1213 | L | P | 1 | 3 | 80005 | 160278 45 | Q | 1214 | W | P | 1 | 5 | 80013 | 160302 46 | Q | 1224 | W | N | 3 | | 80001 | 160531 46 | Q | 1203 | L | N | 1 | | 80002 | 160047 47 | Q | 1208 | W | P | 1 | 6 | 80016 | 160163 47 | Q | 1211 | L | P | 1 | 5 | 80020 | 160231 48 | Q | 1207 | W | N | 5 | | 80021 | 160140 48 | Q | 1210 | L | N | 2 | | 80024 | 160208 49 | S | 1214 | W | N | 2 | | 80011 | 160302 49 | S | 1224 | L | N | 0 | | 80022 | 160531 50 | S | 1207 | W | N | 2 | | 80008 | 160140 50 | S | 1208 | L | N | 1 | | 80019 | 160163 51 | F | 1214 | W | N | 1 | | 80004 | 160302 51 | F | 1207 | L | N | 0 | | 80007 | 160140Sample table: soccer_country
country_id | country_abbr | country_name ------------+--------------+--------------------- 1201 | ALB | Albania 1202 | AUT | Austria 1203 | BEL | Belgium 1204 | CRO | Croatia 1205 | CZE | Czech Republic 1206 | ENG | England 1207 | FRA | France 1208 | GER | Germany 1209 | HUN | Hungary 1210 | ISL | Iceland 1211 | ITA | Italy 1212 | NIR | Northern Ireland 1213 | POL | Poland 1214 | POR | Portugal 1215 | IRL | Republic of Ireland 1216 | ROU | Romania 1217 | RUS | Russia 1218 | SVK | Slovakia 1219 | ESP | Spain 1220 | SWE | Sweden 1221 | SUI | Switzerland 1222 | TUR | Turkey 1223 | UKR | Ukraine 1224 | WAL | Wales 1225 | SLO | Slovenia 1226 | NED | Netherlands 1227 | SRB | Serbia 1228 | SCO | Scotland 1229 | NOR | Norway
Sample Solution:
SQL Code:
-- This SQL query retrieves match numbers from the 'match_details' table
-- where the teams are either Germany or Poland, and each match involves both teams.
SELECT match_no
-- Selects the 'match_no' column.
FROM match_details
-- 'match_details' is the name of the table being queried.
WHERE team_id = (
-- The WHERE clause filters rows where 'team_id' matches the country ID for Germany in the subquery.
SELECT country_id
-- The subquery selects the 'country_id' column.
FROM soccer_country
-- 'soccer_country' is the name of the table involved in the subquery.
WHERE country_name = 'Germany'
)
OR team_id = (
-- The OR condition allows for rows where 'team_id' matches the country ID for Poland in the subquery.
SELECT country_id
-- The subquery selects the 'country_id' column.
FROM soccer_country
-- 'soccer_country' is the name of the table involved in the subquery.
WHERE country_name = 'Poland'
)
GROUP BY match_no
-- Groups the results by 'match_no'.
HAVING COUNT(DISTINCT team_id) = 2;
-- The HAVING clause filters groups where the count of distinct 'team_id' values is equal to 2.
Sample Output:
match_no ---------- 18 (1 row)
Code Explanation:
The said query in SQL that selects the match number from the 'match_details' table where either the team_id is Germany's country_id or Poland's country_id and there are two distinct team_ids associated with that match.
The WHERE clause filters the results to only include rows where the "team_id" column is equal to either Germany's country_id or Poland's country_id.
The GROUP BY clause groups the results by the "match_no" column.
The HAVING clause filters the results to only include groups where there are two distinct values of the "team_id" column.
So, this query will return the match numbers for matches where Germany or Poland participated and there were exactly two teams in the match.
Alternative Solutions:
Using JOIN and WHERE:
SELECT md.match_no
FROM match_details md
JOIN soccer_country sc ON md.team_id = sc.country_id
WHERE sc.country_name IN ('Germany', 'Poland')
GROUP BY md.match_no
HAVING COUNT(DISTINCT md.team_id) = 2;
Explanation:
This query joins match_details with soccer_country based on the team_id and country_id relation. It then filters for matches involving Germany or Poland, groups the results by match number, and ensures that both teams are present in the match.
Using EXISTS:
SELECT match_no
FROM match_details md1
WHERE team_id = (
SELECT country_id
FROM soccer_country
WHERE country_name='Germany'
)
AND EXISTS (
SELECT 1
FROM match_details md2
WHERE md2.match_no = md1.match_no
AND md2.team_id = (
SELECT country_id
FROM soccer_country
WHERE country_name='Poland'
)
);
Explanation:
This query uses two correlated subqueries to find matches where Germany and Poland both participated.
Using INTERSECT:
SELECT match_no
FROM match_details
WHERE team_id = (
SELECT country_id
FROM soccer_country
WHERE country_name='Germany'
)
INTERSECT
SELECT match_no
FROM match_details
WHERE team_id = (
SELECT country_id
FROM soccer_country
WHERE country_name='Poland'
);
Explanation:
This query uses the INTERSECT operator to find matches that involve both Germany and Poland.
Practice Online
Sample Database: soccer
Query Visualization:
Duration:
Rows:
Cost:
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Previous SQL Exercise: Find which was the highest audience match.
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