如何$in正确使用 in $ref?
cursor = db.MyCollection.find({
"player": {
"$ref": "Contact",
"$id": {
$in: [ObjectId("556d901118bfd4901e2a3833"), ObjectId("556d901118bfd4901e2a3833")]
} ^ it executes successfully, but does not find anything
}
})
甚至可以在$in内部使用$ref吗?