In a project step of a mongo aggregation, I'd like to create a boolean field like:
{
$project: {
isInArray: { $cond: [
{ $in: ['$_id', ids] },
{ $const: true },
{ $const: false },
] },
},
},
but this is failing with
invalid operator $in
I could not find documentation on the correct syntax
You can use $setIsSubset operator
db.people.aggregate([
{ $project: {
isInArray: { $cond: [ {$setIsSubset: [['$_id'], ids]}, true, false ] }
}}
])