javascript - How to use php to generate data in json format that can extract hierarchical structure?

The picture shows the structure of a table in the database, pid represents the id of the parent node of the current node
How to use php to generate data in json format that can extract the hierarchical structure?

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The picture shows the structure of a table in the database, pid represents the id of the parent node of the current node
How to use php to generate data in json format that can extract the hierarchical structure?

What form of data do you want? This is handled directly with foreach. Just use json_decode to convert it again