Complex aggregation with multiple lookups & unwinds results in nested arrays

Working with Data
2

Hi @Georg_Bote ,

Welcome to mongodb community.

The initial problem I see is with you schema design. It seems that it is more normalised for sql relational databases than Mongodb document model.

The idea is that data that is queried together should be stored together even in cost of duplicating data sometimes.

For example the flags data can be embedded in the bookings collection, where beside the id the flag you store flag names or any additional data important to your critical queries.

Now the aggregation is complex with multiple stages. You can still reshape the data to get embedded arrays out adding stages:

{
$addFields : { bookingsFlags : { $first : "$bookingsFlags"}}
},
{
$addFields : { bookingsFlags :"$bookingsFlags.name"}
}

Thanks
Pavel