MASTERING THE SHELL

Raw MongoDB (as you like it)

What is the shell?

•vars•funct

ions•data

structs + types

Embedded Javascript Interpreter

•ObjectId("...")

•new Date()

•Object.bsonsize()

Global Functions and Objects

•db["collection"].find/count/update

•short-hand for collections

MongoDB driver Exposed

•Doesn't require quoted keys

•Don’t copy and paste too much

JSON-like stuff

What is it good for?

Debugging Testing Administration Scripting Glue Not building apps, probably

The Bad: JS Types

Numbers Suck (but getting better) 32/64bit signed (int/long) –

1.5.4>NumberLong(“”) Displayed funny Everything is a 64bit fp (double)

Dates are a challenge new Date(“1/1/1”) Not Date(“1/1/1”) -> string

The Bad: JS is Slow

Shell Safe/GLE Loops and updates Data conversions

Server It pretty much applies here too Be careful with numbers as well

Insert, Save, Update, Remove Demo now

for(i = 0; i <1000; i++) { db.test.insert({x:i, ts: new Date()}) }

Command Line

--eval it/cursor Printing values

Pass in a script

Loading Scripts

Command line load() – also runs

Run Commands

db.runCommand({…})

db.runCommand(“getLastError”)

Useful Commands

getCmdLineOpts ping isMaster reIndex sharding replication

Profiling

setProfilingLevel(lvl, <ms>) 0: none 1: time-based 2: all

Reading from profile collection>db.system.profile.find()

Help

> help> help admin> help misc> db.help()> db.coll.help()

Expose Functions

Leave off the () to see the function:

> db.getSisterDBfunction (name) { return this.getMongo().getDB(name);

Cool functions

printjson -> tojson forEach on array/query/cursor> [{x:1},{y:1}].forEach(function(x){printjson(x)})

{ "x" : 1 }

{ "y" : 1 }

Object.bsonsizeObject.bsonsize(c.findOne({name:”scott”}))

load(file) run(file)

Print all Indexes

db.getCollectionNames().forEach(function(x){

print(“Collection: “ + x);printjson(db[x].getIndexes());

})

Getting the Biggest Doc

var cursor = db.coll.find();var biggest=0;var doc = {};cursor.forEach(function (x) {

var size = Object.bsonsize(x); if (size > biggest) { biggest=size; doc = x; }

});

Cursors: it

“it” global var find automatically sets it

Aliases

Show collections/tables

DBRef

Has fetch() Easy to create

Questions

That’s all…folks!

ScottHernandez@gmail.com