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