MongoDB create $lookup on multipe document with LIKE condition - mongodb

Question

Suppose I have 2 documents and I want to make join.
customers document
/* 1 */
{
"_id" : ObjectId("596d5aacb02f922a92475698"),
"code" : "A001",
"name" : "NameA001",
"age" : 35
}
/* 2 */
{
"_id" : ObjectId("596d5aacb02f922a9247569a"),
"code" : "A002",
"name" : "NameA002",
"age" : 52
}
/* 3 */
{
"_id" : ObjectId("596d5aacb02f922a9247569c"),
"code" : "A003",
"name" : "NameA003",
"age" : 47
}
sale document
/* 1 */
{
"_id" : ObjectId("596d5ad3b02f922a924756c3"),
"ucode" : "SL-A001",
"pname" : "Product 1",
"quantity" : 3
}
/* 2 */
{
"_id" : ObjectId("596d5ad3b02f922a924756c5"),
"ucode" : "SL-A001",
"pname" : "Product 2",
"quantity" : 5
}
/* 3 */
{
"_id" : ObjectId("596d5ad3b02f922a924756cd"),
"ucode" : "SL-A002",
"pname" : "Product 3",
"quantity" : 10
}
/* 4 */
{
"_id" : ObjectId("596d5ad3b02f922a924756d1"),
"ucode" : "SL-A003",
"pname" : "Product 8",
"quantity" : 5
}
I want to make join on customers and sale document to get all customers whose age are less than 50. The result looks like
/* 1 */
{
"_id" : ObjectId("596d5aacb02f922a92475698"),
"code" : "A001",
"name" : "NameA001",
"age" : 35,
"history" : [
{
"_id" : ObjectId("596d5ad3b02f922a924756c3"),
"ucode" : "SL-A001",
"pname" : "Product 1",
"quantity" : 3
},
{
"_id" : ObjectId("596d5ad3b02f922a924756c5"),
"ucode" : "SL-A001",
"pname" : "Product 2",
"quantity" : 5
}
]
}
/* 2 */
{
"_id" : ObjectId("596d5aacb02f922a9247569c"),
"code" : "A003",
"name" : "NameA003",
"age" : 47,
"history" : [
{
"_id" : ObjectId("596d5ad3b02f922a924756d1"),
"ucode" : "SL-A003",
"pname" : "Product 8",
"quantity" : 5
}
]
}
I wrote aggregate statement but I dont know how to make LIKE condition on $lookup.
db.customer.aggregate([
{
$match: { "age": { $lt: 50 } }
},
{
$lookup:
{
from: "sale",
localField: "code",
foreignField: "ucode",
as: "history"
}
}
])
How can I write lookup with Like condition on localField or foreignField? (Or any suggestion to join with like condition)
Thank you in advance.