Java 中 MongoDB 文档数组的精确文本匹配

Question

I am trying to retrieve a single document (first) from a collection using an exact match on the MongoDB collection in Java.

The collection is as follows:

{ "_id": 1, "color": "red", "qty": 5, "vendor": ["Vendor A"] }
{ "_id": 2, "color": "purple", "qty": 10, "vendor": ["Vendor C", "Vendor D"] }
{ "_id": 3, "color": "blue", "qty": 8, "vendor": ["Vendor B", "Vendor A"] }
{ "_id": 4, "color": "white", "qty": 6, "vendor": ["Vendor"] }

I want to query and return the document by searching for "Vendor" (string: keySearch) in the vendor tags:

{ "_id": 4, "color": "white", "qty": 6, "vendor": ["Vendor"] }

But, the following code I wrote returns the first document instead:

Bson filter = Filters.text("\"" + keySearch + "\"");
Document doc = collection.find(filter).first();

I also tried the following, but this returns nothing:

Bson elemInArrayMatch = elemMatch("vendor", eq(keySearch));
Document doc = collection.find(elemInArrayMatch).first();

I want to perform an exact match on the vendor tag, ie, when the keySearch is "Vendor" it should return (in this case) only one document, ID: 4. Can anyone help me please?

Answer 1

In Java you can do something like:

private static void findExample(DBCollection collection) {
    BasicDBObject Query = new BasicDBObject();
    Query.put("vendor","Vendor");
    DBCursor cursor = collection.find(Query);
    while (cursor.hasNext()) {
        System.out.println(cursor.next());
    }
}

example from mongoDB java docs here