Which of the following database model, we have a parent-child relationship?

1. hierarchical databases
2. network databases
3. relational databases

Choose the correct answer from the options below:

In a hierarchical database model, data is arranged like a tree.

It clearly follows a parent-child relationship.

So, statement $1$ is correct.

In a network database model, records are connected using links, and it can also represent parent-child type relationships.

So, statement $2$ is also correct.

In a relational database model, data is stored in tables.

It uses relations, primary keys, and foreign keys, but it is not mainly based on a parent-child structure.

So, statement $3$ is not correct.

Therefore, correct statements are:

$1$ and $2$