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_details
match_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 | 160140
Sample 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.
Go to:
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Practice Online
Sample Database: soccer
Query Visualization:
Duration:
Rows:
Cost:
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