Diplaying a pyramid structure from a database

There are very many uses of data such as that. Other names for that kind of data is tree, hierarchical and recursive. It is the kind of data that is shown in a tree control. It is data that forms a hierarchy, as in executives, managers and supervisors and workers in a company. It is recursive in the sense that a record can be a member of a group and can be a group with members. Another relevant name is pyramid.

A hierarchy such as that would be used for any manufactured product with minimal complexity. So for example a jet aircraft has many assemblies with many components and many of the components are assemblies. So engineering drawings would need data such as that. Projects such as large software projects have sub-projects that have sub-projects.

Another example is file systems. Disk drive file systems have a root directory with subdirectories and subdirectories have subdirectories.

I think this gives you more terminology for finding artricles and examples and such. Your solution depends on details that you have not made clear. You say "join two people under his name" and you say "if that person has 15 people under his name" so it is not clear if there is a specified number of "joined" people or a limit or whatever. So I can only be vague but what you need is that each person has an id and they have a list of ids of people "joined" to them. The database can have a relationship from the joined ids to the record for each joined person.

There is a potential problem for data such as that. If someone makes a mistake and enters a record in such a manner that it creates an infinite loop of parent and child relationships, then that could cause your program to go into an infinite loop. There are solutions for that problem but unless you fnd an article or sample about that you might spend a very long time thinking about how to solve the problem. I know that the way that a large aircraft manufacturer solved the problem years ago was a tumble-down (recursive or iterative) process that went from the top to the bottom for each path in the product.

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Sam Hobbs15y ago
There are very many uses of data such as that. Other names for that kind of data is tree, hierarchical and recursive. It is the kind of data that is shown in a tree control. It is data that forms a hierarchy, as in executives, managers and supervisors and workers in a company. It is recursive in the sense that a record can be a member of a group and can be a group with members. Another relevant name is pyramid.

A hierarchy such as that would be used for any manufactured product with minimal complexity. So for example a jet aircraft has many assemblies with many components and many of the components are assemblies. So engineering drawings would need data such as that. Projects such as large software projects have sub-projects that have sub-projects.

Another example is file systems. Disk drive file systems have a root directory with subdirectories and subdirectories have subdirectories.

I think this gives you more terminology for finding artricles and examples and such. Your solution depends on details that you have not made clear. You say "join two people under his name" and you say "if that person has 15 people under his name" so it is not clear if there is a specified number of "joined" people or a limit or whatever. So I can only be vague but what you need is that each person has an id and they have a list of ids of people "joined" to them. The database can have a relationship from the joined ids to the record for each joined person.

There is a potential problem for data such as that. If someone makes a mistake and enters a record in such a manner that it creates an infinite loop of parent and child relationships, then that could cause your program to go into an infinite loop. There are solutions for that problem but unless you fnd an article or sample about that you might spend a very long time thinking about how to solve the problem. I know that the way that a large aircraft manufacturer solved the problem years ago was a tumble-down (recursive or iterative) process that went from the top to the bottom for each path in the product.