MongoDB Haskell Mini Tutorial ----------------------------- __Author:__ Brian Gianforcaro (b.gianfo@gmail.com) __Updated:__ 2/28/2010 This is a mini tutorial to get you up and going with the basics of the Haskell mongoDB drivers. It is modeled after the python tutorial pymongo available here: http://api.mongodb.org/python/1.4%2B/tutorial.html You will need the mongoDB bindings installed as well as mongo itself installed. >$ = command line prompt > = ghci repl prompt Installing Haskell Bindings --------------------------- From Source: > $ git clone git://github.com/srp/mongoDB.git > $ cd mongoDB > $ runhaskell Setup.hs configure > $ runhaskell Setup.hs build > $ runhaskell Setup.hs install From Hackage using cabal: > $ cabal install mongoDB Getting Ready ------------- Start a MongoDB instance for us to play with: > $ mongod Start up a haskell repl: > $ ghci Now We'll need to bring in the MongoDB/BSON bindings: > import Database.MongoDB > import Database.MongoDB.BSON Making A Connection ------------------- Open up a connection to your DB instance, using the standard port: > con <- connect "127.0.0.1" or for a non-standard port > import Network > con <- connectOnPort "127.0.0.1" (Network.PortNumber 666) Getting the Databases ------------------ > dbs <- databaseNames con > let testdb = head dbs Getting the Collections ----------------------- > collections <- collectionNames con testdb > let testcol = head collections Documents --------- BSON representation in Haskell Inserting a Document ------------------- > insert con testcol (toBsonDoc [("author", toBson "Mike"), ("text", toBson "My first Blog post!"), ("tags", toBson ["mongodb", "python","pymongo"])]) Getting a single document with findOne ------------------------------------- > findOne con curcol (toBsonDoc [("author", toBson "Mike")]) Querying for More Than One Document ------------------------------------ > cursor <- find con curcol (toBsonDoc [("author", toBson "Mike")]) > allDocs cursor See nextDoc to modify cursor incrementally one at a time. * Note: allDocs automatically closes the cursor when done, through nextDoc. Counting -------- We can count how many documents are in an entire collection: > num <- count con testcol Or we can query for how many documents match a query: > num <- countMatching con testcol (toBsonDoc [("author", toBson "Mike")]) Range Queries ------------- No non native sorting yet. Indexing -------- WIP - coming soon. Something like... > index <- createIndex con testcol [("author", Ascending)] True