What schema structure to use for this app? - reactjs

Question

I want to create an expense tracking app but don't know how to make my schema structure.
The layout:
The schema:
module.exports = {
expenseList: [
{
uid: 'some-uid1',
createdAt: 'some-date1',
expenseItems: [
{
date: 'date11',
desc: 'desc11',
amount: 'amount11'
},
{
date: 'date11',
desc: 'desc11',
amount: 'amount11'
}]
},
{
uid: 'some-uid',
createdAt: 'some-date',
expenseItems: [
{
date: 'date1',
desc: 'desc1',
amount: 'amount1'
},
{
date: 'date1',
desc: 'desc1',
amount: 'amount1'
},
{
date: 'date1',
desc: 'desc1',
amount: 'amount1'
}]
}
]
};
How do I change my schema so I can loop through expenses and display createdAt property as a clickable link that redirects to that expense items?
When do I use Arrays and when do I use Objects in my schema?
Where do I need uid (unique ids)?
I will use firebase for this app

Answer 1

You have an expenseList with a date and expenseItems associated with it. You can have a schema roughly like this. expenseList will be an array of objects. Each expenseList is an object containing uid (to uniquely identify the list), createdAt and array of expenseItems with its own set of properties.
expenseList: [{
uid: 'some-uid',
createdAt: 'some-date',
expenseItems: [
{
date: 'date1',
desc: 'desc1',
amount: 'amount1'
},
{
date: 'date1',
desc: 'desc1',
amount: 'amount1'
}
]
}]
You can iterate over this expenseList to display createdAt in your first screen. On clicking of that, depending on the unique id of that expenseList, fetch the expenseList and display the expenseItems on the second screen.
I have not used firebase before, so you might have to tweak the schema a little.