訪問DataBase

當已經有一個初始化好的MongoClient后，通過如下方式來訪問一個database，示例如下：

MongoDatabase memberInfoDatabase = mongoClient.getDatabase("MemberInfo");

訪問集合

當獲取一個MongoDatabase實例后，可以通過如下命令來得到要獲取的集合：

MongoCollection<Document> coll = memberInfoDatabase.getCollection("gold_member");

顯示的創建一個集合

也可以通過 createCollection()方法顯示的創建一個集合，并在創建時候指定該集合的屬性。

memberInfoDatabase.createCollection("testCollection", new CreateCollectionOptions().sizeInBytes(200000));

插入數據

Document doc0 = new Document("name", "萬三")
 ? ? ?  .append("age", 30)
 ? ? ?  .append("sex", "male");
?
Document doc1 = new Document("name", "劉亞")
 ? ? ?  .append("age", 42)
 ? ? ?  .append("sex", "male");
?
Document doc2 = new Document("name", "王瑩")
 ? ? ?  .append("age", 22)
 ? ? ?  .append("sex", "female");
?
List<Document> documents = new ArrayList<>();
documents.add(doc0);
documents.add(doc1);
documents.add(doc2);
goldMemberCollection.insertMany(documents);

刪除數據

goldMemberCollection.deleteOne(eq("name", "劉亞"));

刪除表

MongoCollection<Document> collection = memberInfoDatabase.getCollection("test");
collection.drop();

讀數據

MongoCursor<String> cursor = (MongoCursor<String>) goldMemberCollection.find();
while (cursor.hasNext())  {
 ? ?Object result = cursor.next();
}
cursor.close();

帶過濾條件的查詢

MongoCursor<String> cursorCondition = (MongoCursor<String>)goldMemberCollection.find(
 ? ? ? ?new Document("name","zhangsan")
 ? ? ? ? ? ? ?  .append("age", 5));
while (cursorCondition.hasNext())  {
 ? ?Object result = cursorCondition.next();
}
cursorCondition.close();

運行命令

執行buildInfo和collStats：

MongoClient mongoClientShell = (MongoClient) MongoClients.create();
MongoDatabase database = mongoClientShell.getDatabase("MemberInfo");
?
Document buildInfoResults = database.runCommand(new Document("buildInfo", 1));
System.out.println(buildInfoResults.toJson());
?
Document collStatsResults = database.runCommand(new Document("collStats", "restaurants"));
System.out.println(collStatsResults.toJson());

創建索引

MongoCollection<Document> collectionTest = memberInfoDatabase.getCollection("gold_member");
collectionTest.createIndex(Indexes.ascending("age"));