I want to find if field_1 matches the beginning of field_2 within a document, using MongoDB Shell, and get the count of documents that matches and that does not match.
field_1 and field_2 are in the same document, and there are about 180k documents.
field_1: 2 numbers in string type (Ex. '10', '40', '15')
field_2: 8 numbers in string type (Ex. '10102020', '40204010')
Below is my code so far. It returns nothing.
db.coll_1.find().forEach(
function(x) {
db.coll_1.find({
field_1: {$regex: /^x.field_2*/}
})
Query
db.collection.aggregate([
{
"$group": {
"_id": null,
"n-match": {
"$sum": {
"$cond": [
{
"$eq": [
"$field1",
{
"$substrCP": [
"$field2",
0,
2
]
}
]
},
1,
0
]
}
},
"n-not-match": {
"$sum": {
"$cond": [
{
"$ne": [
"$field1",
{
"$substrCP": [
"$field2",
0,
2
]
}
]
},
1,
0
]
}
}
}
},
{
"$project": {
"_id": 0
}
}
])