# user
{
	(_id)
	id : string, required,
	name : string, required,
	pwd : string
	accountbook : [_id ...]
}

# account book
{
	(_id)
	name : string
	description : string
	transaction : [_id]
}

# transaction
{
	(_id)
	content : string
	type : string (수입/지출)
	cost : number
	date : date
}

# category
{
	(_id)
	name : string
	icon : number	
}

# payment
{
	(_id)
	card : number
	description : string
}

---

# user 
{
    (_id)
    id : string
    name : string
    pwd : string
}

#default_category: [{
           (_id)
            name : string
            icon : number

}]

#default_payment: [
{
             (_id)
            card : number
            description : string
}
]

# account book
{
    (_id)
    name : string
    description : string
    category: [
        {
            (_id)
            icon : number	
        }
    ]
            name : string
    payment: [
        {
            (_id)
            card : number
            description : string
        }
    ]
    user: [
        (_id),(_id),(_id)
    ]
    transaction : [
        {
            (_id)
            content : string
            type : string (수입/지출)
            cost : number
            date : date
            category: {
                name : string
                icon : number
            }
            payment: {
                card: number
                description : string
            }
        },
        {
            (_id)
            content : string
            type : string (수입/지출)
            cost : number
            date : date
            category: {     
                name : string
                icon : number
            }
            payment: {
                card: number
                description : string
            }
        },
    ]
}