Date range filter and One-to-Many relation query syntax - prisma

Question

I am trying to filter booked rooms to find all available rooms:
model Room {
id Int #id #default(autoincrement())
roomNumber String #unique
hotel String
bookings Booking[]
}
model Booking {
id Int #id #default(autoincrement())
hotel String
startDate DateTime
endDate DateTime
roomId Int
room Room #relation(fields: [roomId], references: [id])
##map("bookings")
}
I don't get the syntax of a prisma findMany query that would check, given two booking dates, all available rooms.
The mathematical logic to find if a room is not available is (i.e. if one booking interval crosses or contains the dates given) :
(startDate <= dto.startDate && dto.startDate < endDate) ||
(startDate < dto.endDate && dto.endDate <= endDate) ||
(dto.startDate <= startDate && dto.endDate >= endDate)
I would appreciate any help as I don't understand quite well the order of logic filters in prisma...

Answer 1

You can use none:
prisma.room.findMany({
where: {
bookings: {
none: {
// ...
},
},
},
});
and specify the condition for a booking that would case a conflict (i.e. make the room not available) or use every:
prisma.room.findMany({
where: {
bookings: {
every: {
//...
},
},
},
});
and specify the condition that bookings have to meet to not cause a conflict.
The condition you've specified seems unnecessary complex to me. Every booking that meets this condition should be a conflict:
(dto.startDate <= endDate && dto.endDate >= startDate)
(might need some adjustment depending on how you want to treat edge cases)
All together:
prisma.room.findMany({
where: {
bookings: {
none: {
endDate: { lte: dto.startDate },
startDate: { gte: dto.endDate },
},
},
},
});
Just in case you want to specify more complex conditions using OR you can do like this:
prisma.room.findMany({
where: {
bookings: {
none: {
OR: [
{
// (startDate <= dto.startDate && dto.startDate < endDate)
startDate: { lte: dto.startDate },
endDate: { gt: dto.startDate },
},
{
// (startDate < dto.endDate && dto.endDate <= endDate)
startDate: { lt: dto.endDate },
endDate: { gte: dto.endDate },
},
{
// (dto.startDate <= startDate && dto.endDate >= endDate)
startDate: { gte: dto.startDate },
endDate: { lte: dto.endDate },
},
],
},
},
},
});