1 -- 1 single FK import, data table
6 foreign key (b_id) references b (b_id),
10 -- standalone, data table
17 -- 1 single FK import, link table between 'a' and 'b'
19 a_b_id serial not null,
22 foreign key (a_id) references a (a_id),
24 foreign key (b_id) references b (b_id)
27 -- 1 single FK import, data table
32 foreign key (b_id) references b (b_id),
36 -- 1 single FK import, data table
41 foreign key (c_id) references c (c_id),
45 -- standalone, data table
52 -- 2 single FK import, link table between 'c' and 'e'
54 c_e_id serial not null,
57 foreign key (c_id) references c (c_id),
59 foreign key (e_id) references e (e_id)
62 -- 1 triple FK import, link table between 'e', 'e', and 'e'
67 foreign key (e1_id) references e (e_id),
69 foreign key (e2_id) references e (e_id),
71 foreign key (e3_id) references e (e_id)
74 -- 1 single FK import, 1 double FK import, link table between 'a', 'e', and 'e'
79 foreign key (a_id) references a (a_id),
81 foreign key (e1_id) references e (e_id),
83 foreign key (e2_id) references e (e_id)
86 -- 1 double FK import, 1 triple FK import, link table between 'a', 'a', 'g', 'g', and 'g'
91 foreign key (a1_id) references a (a_id),
93 foreign key (a2_id) references a (a_id),
95 foreign key (g1_id) references g (g_id),
97 foreign key (g2_id) references g (g_id),
99 foreign key (g3_id) references g (g_id)