How to use php to output the provinces and corresponding cities across the country based on city codes

id fid name

The same idea as classification,

Add a fid to the city table to record the ID of the province to which it belongs

Provincial level Then fid is 0

With the province id, take out the corresponding city select * form city where fid = id;

According to the name of the province, first find out the id corresponding to the province, and then check the corresponding city