在Oracle SQL中加入多个条件

Question

I've got a table of data of two columns (User_id and ForeignUser_id). So these columns I also have in the other table with a column of category (one for all). What should I do to get the set of data like

User_ID Category ForeignUser_ID Category

I used union and cte functions but need to get the data in the structure as above so it wasn't helpful.

the first table UserModel:

User_ID ForeignUser_ID
1234       2568
1234       6589
3333       4426
3333       2635
4252       6235
4252       5986

the second table Users:

 User_ID Category
    1234       A
    3333       B
    4252       A
    2568       B
    6589       B
    4426       A
    2635       C
    6235       C
    5986       B

The desired outcome:

User_ID    Category  ForeignUser_ID    Category  
    1234       A          2568            B
    1234       A          6589            B
    3333       B          4426            A
    3333       B          2635            C
    4252       A          6235            C
    4252       A          5986            B

Answer 1

you will need to do two joins to get this result

Select um.User_ID, us1.Category, um.ForeignUser_ID, us2.Category    
From UserModel um inner join Users as us1 on (um.User_ID = us1.User_ID)
                  inner join Users as us2 on (um.ForeignUser_ID = us2.User_ID)