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Hash Join Algorithm from MySQL in Python

Assume I want to write the following SQL Query:

SELECT Employee.Name, Employee.ID, InvitedToParty.Name, InvitedToParty.FavoriteFood
FROM Employee, InvitedToParty
WHERE Employee.ID = InvitedToParty.ID

given the required tables :

Employee

ID  Name     Birthday
1   Heiny    01.01.2000
2   Peter    10.10.1990
3   Sabrina  12.10. 2015
.
.

InvitedToParty

Name    FavoriteFood
Michael Pizza
Heiny   Pizza
Sabrina Burger
George  Pasta
.
.
.

Assume I have this information as two lists in Python inside a dictionary:

tables['Employee'].id = [1, 2, 3 ..]
tables['Employee'].Name = [Heiny, Peter, Sabrina ...]

I hope you get the idea. These keys of the dictionary have attributes, because I created a class for each table.

How can I write this query in Python? My initial idea was (pseudo):

match_counter = 0

for i, value in enumerate(table1.column):

    for j in range(len(table2.column)):

        if table2.column[j] == value:

            table2.column[j], table2.column[i] = table2.column[i], table2.column[]
            match_counter += 1

And remove everything after 'match_counter' rows. But I am sure there must be a better way? Moreover, I do not even know if this would give me the correct result



source https://stackoverflow.com/questions/72720903/hash-join-algorithm-from-mysql-in-python

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