This document introduces MongoDB, an open source document database that is horizontally scalable and high performance. It discusses MongoDB terminology and how it differs from relational databases. Examples are provided for common operations like CRUD, indexing, querying, aggregation, map-reduce, and examples are provided to demonstrate usage. Resources for learning more about MongoDB are listed at the end.

1. Introduction to MongoDB
for C# developers
by Taras Romanyk – rredcat@gmail.com
http://www.linkedin.com/in/rredcat

2. What is it?
● Document
● Open source
● High performance
● Horizontally scalable

3. Terminology
RDBMS MongoDB
Table, View Collection
Row Document
Index Index
Join Embedded Document
Foreign Key Reference
Partition Shard

4. What is it?
BSON
{
"_id":
ObjectId("4efa8d2b7d284dad101e4bc7"),
"Last Name": "PELLERIN",
"First Name": "Franck",
"Date of Birth": "09-19-1983",
"Address": "1 chemin des Loges",
"City": "VERSAILLES"
}

5. CRUD
{ _id: 1, highScore: 800, lowScore: 200 }
● 16 MB limitation
● GridFS (chunks, files) partly loading
● $inc, $mul, $rename, $setOnInsert,
$set,$unset, $min, $max, $currentDate

6. CRUD
{ _id: 1, highScore: 800, lowScore: 200 }
{ _id: 1, highScore: 800, lowScore: 200 }
db.scores.update(
{ _id: 1 },
{ $min: { lowScore: 150 } }
)

7. Find/Aggregation
Find
db.inventory.find( { type: 'food', price: { $lt: 9.95 } } )
Aggregation
$project, $match, $limit, $skip, $unwind,
$group, $sort, $geoNear, $out, $redact
$out
$out

8. Find/Aggregation
{"_id": "10", "city": "NEW YORK", "state": "NY",
"pop": 5574}
db.zipcodes.aggregate(
{ $group :{
_id : { state : "$state", city : "$city" },
pop : { $sum : "$pop" } } },
{ $group : {
_id : "$_id.state",
avgCityPop : { $avg : "$pop" }
} } )

9. MapReduce
var map =
"function() {" +
" for (var key in this) {" +
" emit(key, { count : 1 });" +
" }" +
"}";
var reduce =
"function(key, emits) {" +
" total = 0;" +
" for (var i in emits) {" +
" total += emits[i].count;" +
" }" +
" return { count : total };" +
"}";
var mr = collection.MapReduce(map, reduce);
foreach (var document in mr.GetResults()) {
Console.WriteLine(document.ToJson());
}

10. Exmaple

11. Example

12. Example

13. Example

14. Q&A
https://university.mongodb.com/courses
http://docs.mongodb.org/manual/
http://www.10gen.com/presentations
https://groups.google.com/forum/#!forum/mo
ngodb-user
http://stackoverflow.com/questions/tagged/m
ongodb
http://robomongo.org/