How to delete all documents in mongodb collection in java

Question

I want to delete all documents in a collection in java. Here is my code: MongoClient client = new MongoClient("10.0.2.113" , 27017); MongoDatabase db = client.getDatabase("maindb"); db.getCollection("mainCollection").deleteMany(new Document()); Is this the correct way to do this? I am using MongoDB 3.0.2

Answer 1

使用API​​＆gt; = 3.0：

MongoClient mongoClient = new MongoClient("127.0.0.1" , 27017);
MongoDatabase db = mongoClient.getDatabase("maindb");
db.getCollection("mainCollection").deleteMany(new Document());

要删除集合（文档和索引），您仍然可以使用：

db.getCollection("mainCollection").drop();

请参阅https://docs.mongodb.org/getting-started/java/remove/#remove-all-documents

Answer 2

To remove all documents use the BasicDBObject or DBCursor as follows: MongoClient client = new MongoClient("10.0.2.113" , 27017); MongoDatabase db = client.getDatabase("maindb"); MongoCollection collection = db.getCollection("mainCollection") BasicDBObject document = new BasicDBObject(); // Delete All documents from collection Using blank BasicDBObject collection.deleteMany(document); // Delete All documents from collection using DBCursor DBCursor cursor = collection.find(); while (cursor.hasNext()) { collection.remove(cursor.next()); }

Answer 3

If you want to remove all documents in collection then used below code : db.getCollection("mainCollection").remove(new BasicDBObject()); Or If you want to drop whole collection then used this : db.getCollection("mainCollection").drop();

Answer 4

对于较新的mongodb驱动程序，您可以使用FindIterable删除集合中的所有文档。

FindIterable<Document> findIterable = collection("mainCollection").find();
       for (Document document : findIterable) {
         collection("mainCollection").deleteMany(document);
       }