gistfile1.txt

+----+------------+----------+--------+------------+------------+
| id | dataset_id | start_id | end_id | created_at | deleted_at |
+----+------------+----------+--------+------------+------------+
|  1 |          1 |       12 |  13348 | NULL       | NULL       |
|  2 |          1 |      107 |  13348 | NULL       | NULL       |
|  3 |          1 |      274 |  13348 | NULL       | NULL       |
|  4 |          1 |      324 |  13348 | NULL       | NULL       |
|  5 |          1 |      418 |  13348 | NULL       | NULL       |
|  6 |          1 |      422 |  13348 | NULL       | NULL       |
|  7 |          1 |      455 |  13348 | NULL       | NULL       |
|  8 |          1 |      456 |  13348 | NULL       | NULL       |
|  9 |          1 |      509 |  13348 | NULL       | NULL       |
| 10 |          1 |      544 |  13348 | NULL       | NULL       |
| 11 |          1 |       12 |  13349 | NULL       | NULL       |
| 12 |          1 |      107 |  13349 | NULL       | NULL       |
| 13 |          1 |      274 |  13349 | NULL       | NULL       |
| 14 |          1 |      324 |  13349 | NULL       | NULL       |
| 15 |          1 |      418 |  13349 | NULL       | NULL       |
| 16 |          1 |      422 |  13349 | NULL       | NULL       |
| 17 |          1 |      455 |  13350 | NULL       | NULL       |
| 18 |          1 |      456 |  13350 | NULL       | NULL       |
| 19 |          1 |      509 |  13350 | NULL       | NULL       |
| 20 |          1 |      544 |  13350 | NULL       | NULL       |
+----+------------+----------+--------+------------+------------+



#With data in a structure like this, how would I be able to find out the intersections of start_id from end_id? In other words, end_id of 
#13348 and 13349 have 6 similar start_id rows (start_ids of 12,107,274,324,418,422), 13348 and 13350 have 4 (455,456,509,544), and 13349 
#and 13350 have zero similar rows.