Check out example codes for "parent and child link in mysql". It will help you in understanding the concepts better.

Code Example 1

table_children
parent child
0      0
1      1
2      2
3      3
4      4
0      1
0      2
0      3
0      4
1      2
1      3
1      4
3      4

Learn ReactJs, React Native from akashmittal.com