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Foreign keys
Multi-column foreign keys
Sample data
P
p1_id
p2_id
x
1
10
123
2
20
456
3
30
789
F
f_id
p1_id
p2_id
y
1001
1
10
999
1002
1
10
888
2001
2
20
777
3001
3
30
666
3002
3
30
555
3003
3
30
444
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