2026-03-12 21:01:38

tiddlywiki/MongoDB - scratchpad.txt

@@ -0,0 +1,35 @@
+> use db01
+-- create database db01 if it does not exists
+> db
+-- show current database
+> show dbs
+-- list databases
+-- db01 is not listed until it does not contain at least a document
+> db.movies.insertOne({"title" : "Stand by Me"})
+
+
+-- create index
+> db.users.createIndex({"age" : 1, "username" : 1});
+
+-- list indexes of a collection
+> db.users.getIndexes();
+
+-- show explain plan
+> db.users.find({"username": "user999999", "age":"19"}).explain("executionStats");
+
+# https://www.mysoftkey.com/mongodb/how-to-enable-authentication-and-authorization-using-scram-sha-1-in-mongodb/
+
+-- Connection String URI Format
+https://docs.mongodb.com/manual/reference/connection-string/index.html#connections-dns-seedlist
+
+-- shutdown MongoDB
+> use admin
+> db.shutdownServer();
+
+-- count(*) of a collection
+db.elements.countDocuments({})
+-- truncte a collection
+db.elements.remove({})
+-- display the last 5 inserted documents of a collection
+db.elements.find().sort({_id:-1}).limit(5);
+