Di DocumentDB doc :
Dalam dokumen MongoDB :
persamaan kesetaraan memiliki sintaks berikut:
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>,
as: <output array field>
}
}
subkueri yang tidak berkorelasi memiliki sintaks berikut:
{
$lookup:
{
from: <collection to join>,
let: { <var_1>: <expression>, …, <var_n>: <expression> },
pipeline: [ <pipeline to execute on the collection to join> ],
as: <output array field>
}
}
Jadi sintaks ke-2 tidak didukung di DocumentDB.