# install on centos
sudo vi /etc/yum.repos.d/mongodb-org-3.4.repo
# add
[mongodb-org-3.4]
name=MongoDB Repository
baseurl=<https://repo.mongodb.org/yum/amazon/2013.03/mongodb-org/3.4/x86_64/>
gpgcheck=1
enabled=1
gpgkey=<https://www.mongodb.org/static/pgp/server-3.4.asc>
sudo yum install -y mongodb-org
# dump
./mongodump --host <host> --port <port> --username <username> --password <password> --out <output_dir> --db <db>
# restore
mongorestore --host <host> --port <port> --username <username> --password <password> <backup_dir>
# start service
sudo service mongod start
./mongod --maxConns 20000 --config /root/mongodb/bin/mongodb.conf
./mongod -f /root/mongodb/bin/mongodb.conf --shutdown
// show users
db.getUsers();
// create
db.createUser({
user: "new_user",
pwd: "new_password",
roles: [{ role: "dbOwner", db: "my_db" }],
mechanisms: ["SCRAM-SHA-1"],
});
// updat
db.updateUser("user_name", {
pwd: "password",
roles: [{ role: "read", db: "my_db" }],
});
// create role
db.getSiblingDB("my_db").createUser({
user: "new_user",
pwd: "new_password",
roles: [{ role: "readWrite", db: "my_db" }],
});
// get role
db.getRole("new_user");
db.getRoles();
// grant roledb.copyDatabase("source_db", "target_db");// create collection
db.createCollection("new_collection");
// batch rename collections with prefix
db.getCollectionInfos().forEach((col) =>
db.getCollection(col.name).renameCollection("prefix" + col.name)
);
// batch delete collection with prefix
db.getCollectionInfos().forEach((col) => {
if (col.name.startsWith("prefix")) {
db.getCollection(col.name).drop();
}
});
// copy from source_collection to target_collection
db.source_collection.find().forEach(function (v) {
db.target_collection.insert(v);
});// distinct
db.my_collection.distinct("key.nested_key",{$find})
view_date:{$gte: ISODate("2018-01-25T00:00:00.000Z"),$lt: ISODate("2018-03-23T00:00:00.000Z")}})
// update nested value
db.my_collection.updateOne({"key.nested_key":"value"},{$set:{"key.nested_key":"new_value"}})
// update new array item
db.my_collection.updateOne({"key":"value"},{$push:{"array_key":"new_item"}})
// update many
db.my_collection.updateMany({'key':'value'},{$set:{'key':'new_value'}});
// rename key
db.my_collection.updateMany({}, {$rename: {"old_key": "new_key"}})
// delete key
db.my_collection.updateMany({}, {$unset: {"key": ""}})
// delete key that not ends with 2
db.my_collection.deleteMany({'key':{$not:/2$/}})
// swap key
db.my_collection.find({}).forEach( function (doc) {
var col1 = doc.col2;
var col2 = doc.col1
doc.col1 = col1;
doc.col2 = col2
db.my_collection.save(doc);
});// count total number of matched documents
db.my_collection.aggregate([
{
$match: {
"time": {
$gt: 1535760000000,
$lt: 1538352000000,
}
}
},
{
$count: "total"
}
]).toArray();
// group by $user and accumulate each time
db.my_collection.aggregate([
{
$match: {
"time": {
$gt: 1525363200000,
$lt: 15260832000000,
}
}
},
{
$group: {
_id: "$user",
uniqueCount: {$addToSet: "$time"}
}
}
]).toArray()
// group by key and formatted time, sort
db.my_collection.aggregate([
// use regex
{
$match: {
"key":{$regex:/abc.*/,$options:'i'}
}
},
// convert date
{
$project: {
key:"key",
date: { $add: [new Date(0), "$time"] }
}
},
// formate date
{
$project: {
key: "$key",
day: {
$dateToString: { format: " %Y-%m-%d", date: "$date" }
}
}
},
// group by day and key
{
$group: {
_id: { day:"day", key:"key"},
count: { $sum: 1 }
}
},
// flatten
{
$project: {
_id: 0,
key: "$_id.key",
day: "$_id.day",
count: "$count"
}
},
// sort
{
$sort: {
"count": -1,
"key": 1,
"day": -1
}
}
]).toArray()
// lookup other collection
db.collection.aggregate([
{
$group:{
_id: "$key",
times: {$addToSet:"$time"}
}
},
{
$lookup:{
from: "another_collection",
localField: "_id",
foreignField: "lookup_key",
as: "another_key"
}
},
{
$project: {
_id: 1,
total: {$size: "$times"},
key: {$arrayElemAt:["another_key", 0]},
}
}
]).toArray()
// print to csv
var cursor = db.my_collection.aggregate([
...
])
if (cursor && cursor.hasNext()) {
print('key1,key2,key3,key4');
while (cursor.hasNext()) {
var item = cursor.next();
print(tem.key1 + ',' + item.key2 + ',' + item.key3 + ',' + item.key4);
}
}
// print to csv
db.my_collection.aggregate([
...
]).to_csv()
// find unique and dedup
var duplicates = []
db.getCollection('my_collection').aggregate([
{
$group: {
_id: {key1:"key1", key2:"key2"},
uniqueIds: {$addToSet: "$_id"},
count: {$sum: 1}
}
},
{
$match: {
count: {"$gt": 1}
}
}
])
.toArray()
.forEach(function(doc) {
doc.uniqueIds.shift();
doc.uniqueIds.forEach( function(dupId){
duplicates.push(dupId);
})
})
db.getCollection('my_collection').remove({_id:{$in:duplicates}})
// find all keys
var allKeys = {};
function traverse(obj,prefix){
Object.keys(obj).forEach(function(k){
var key = prefix + k
if(allKeys.hasOwnProperty(key)){
allKeys[key] = allKeys[key] +1
}else{
allKeys[key]=1
}
if (typeof obj[k] === 'object'){
traverse(obj[k], key+".")
}
})
}
var docs = db.getCollection('my_collection').find({}).toArray()
for (let doc of docs){
traverse(doc,'')
}// DBCommandCursor is for aggregate, DBQuery is for .find()
DBCommandCursor.prototype.to_csv = DBQuery.prototype.to_csv = function (
deliminator,
textQualifier
) {
var count = -1;
var headers = [];
var data = {};
var cursor = this;
deliminator = deliminator == null ? "," : deliminator;
textQualifier = textQualifier == null ? '"' : textQualifier;
while (cursor.hasNext()) {
var array = new Array(cursor.next());
count++;
for (var index in array[0]) {
if (headers.indexOf(index) == -1) {
headers.push(index);
}
}
for (var i = 0; i < array.length; i++) {
for (var index in array[i]) {
data[count + "_" + index] = array[i][index];
}
}
}
var line = "";
for (var index in headers) {
line += textQualifier + headers[index] + textQualifier + deliminator;
}
line = line.slice(0, -1);
print(line);
for (var i = 0; i < count + 1; i++) {
var line = "";
var cell = "";
for (var j = 0; j < headers.length; j++) {
cell = data[i + "_" + headers[j]];
if (cell == undefined) cell = "";
line += textQualifier + cell + textQualifier + deliminator;
}
line = line.slice(0, -1);
print(line);
}
};db.collection.getIndexes();
db.collection.dropIndex("my_index_name");db.stats(1024);
// all collection stats
db.getCollectionNames().forEach((col) => {
print(col);
print(db.getCollection(col).stats(1024 * 1024 * 1024));
});