I have this two tables.
| id | city |
|---|---|
| 1 | bogota |
| 2 | tunja |
| id | branch | cityid |
|---|---|---|
| 1 | sector1 | 1 |
| 2 | sector2 | 2 |
| 3 | sector3 | 2 |
| 4 | sector4 | 1 |
now i need to create a way in which the branch select field updates depending on the foreign key of the city
example: my first combo should contain city bogota and the next combo should only show me the list of branches that are part of that particular city.
how to begin?