Adding rows in a table from data that is not in a column - sql

Question

I'm trying to create a table to add all Medals won by the participant countries in the Olympics.
I scraped the data from Wikipedia and have something similar to this:
Year
Country_Name
Host_city
Host_Country
Gold
Silver
Bronze
1986
146
Los Angeles
United States
41
32
30
1986
67
Los Angeles
United States
12
12
12
And so on
I double-checked the data for some years, and it seems very accurate. The Country_Name has an ID because I have a Country_ID table that I created and updated the names with the ID:
Country_ID
Country_Name
1986
1
1986
2
So far so good. Now I want to create a new table where I'll have all countries in a specific year and the total medals for that country. I managed to easily do that for countries that participated in an edition, here's an example for the 1896 edition:
INSERT INTO Cumultative_Medals_by_Year(Country_ID, Year, Culmutative_Gold, Culmutative_Silver, Culmutative_Bronze, Total_Medals)
SELECT a.Country_Name, a.Year, SUM(a.Gold) As Cumultative_Gold, SUM(a.Silver) As Cumultative_Silver, SUM(a.Bronze) As Cumultative_Bronze, SUM(a.Gold) + SUM(a.Silver) + SUM(a.Bronze) AS Total_Medals
FROM Country_Medals a
Where a.Year >= 1896 AND Year < 1900
Group By a.Country_Name, a.Year
And I'll have this table:
Country_ID
Year
Cumultative_Gold
Cumultative_Silver
Cumultative_Bronze
Total_Medals
6
1986
2
0
0
5
7
1986
2
1
2
5
35
1986
1
2
3
6
46
1986
5
4
2
11
49
1986
6
5
2
13
51
1986
2
3
2
7
52
1986
10
18
19
47
58
1986
2
1
3
6
85
1986
1
0
1
2
131
1986
1
2
0
3
146
1986
11
7
2
20
To add the other editions I just have to edit the dates, "Where a.Year >= 1900 AND Year < 1904", for example.
INSERT INTO Cumultative_Medals_by_Year(Country_ID, Year, Culmutative_Gold, Culmutative_Silver, Culmutative_Bronze, Total_Medals)
SELECT a.Country_Name, a.Year, SUM(a.Gold) As Cumultative_Gold, SUM(a.Silver) As Cumultative_Silver, SUM(a.Bronze) As Cumultative_Bronze, SUM(a.Gold) + SUM(a.Silver) + SUM(a.Bronze) AS Total_Medals
FROM Country_Medals a
Where a.Year >= 1900 AND Year < 1904
Group By a.Country_Name, a.Year
And the table will grow.
But I'd like to also add all the other countries for the year 1896. This way I'll have a full record of all countries. So for example, you see that Country 1 has no medals in the 1896 Olympic edition, but I'd like to also add it there, even if the sum becomes NULL (where I'll update with a 0).
Why do I want that? I'd like to do an Animated Bar Chart Race, and with the data I have, some counties go "away" from the race. For example, the US didn't participate in the 1980 Olympics, so for a brief moment, the Bar for the US in the chart goes away just to return in 1984 (when it participated again). Another example is the Soviet Union, even though they do not participate anymore, it's the second participant with most medals won (only behind the US), but as the country does not have more participation after 1988, the bar just goes away after that year. By keeping a record of medals for all countries in all editions would prevent that from happening.

Answer 1

I'm pretty sure there are lots of countries that have won metals that were not around in 1896. But if you want a row for every country and every year, then generate the rows you want using cross join. Then join in the available information:
select c.Country_Name, y.Year,
SUM(cm.Gold) As Cumulative_Gold,
SUM(cm.Silver) As Cumulative_Silver,
SUM(cm.Bronze) As Cumulative_Bronze,
COALESCE(SUM(cm.Gold), 0) + COALESCE(SUM(cm.Silver), 0) + COALESCE(SUM(cm.Bronze), 0) AS Total_Medals
from (select distinct year from Country_Medals) y cross join
(select distinct country_name from country_medals) c left join
country_medals cm
on cm.year = y.year and
cm.country_name = c.country_name
group By c.Country_Name, y.Year