hvr / hasbolt

Haskell driver for Neo4j 3+ (BOLT protocol)

HasBOLT

Haskell driver for Neo4j 3+ (BOLT protocol)

Documentation

To build Haddock documentation run:

$ stack haddock

Usage example

NB! For a real-world example please see: hasbolt-sample-app.

To use all the magic just import:

λ> import Database.Bolt

To create new connection use (it is highly recommended to use with resource-pool):

λ> pipe <- connect $ def { user = "neo4j", password = "neo4j" }

To make query (query takes Data.Text, so I use OverloadedStrings here):

λ> records <- run pipe $ query "MATCH (n:Person) WHERE n.name CONTAINS \"Tom\" RETURN n"

You can also use parameters by queryP. You have to use T constructor here for text parameter, as Haskell is strong-typed language (see more about values in Data.Value.Type):

λ> records <- run pipe $ queryP "MATCH (n:Person) WHERE n.name CONTAINS {name} RETURN n" (fromList [("name", T "Tom")])

To obtain data from record you can use at and set of exact functions (the last one works for all possible Neo4j data, including primitive types, nodes, relationships and paths). So, you can do something like this:

toNode :: Monad m => Record -> m Node
toNode record = record `at` "n" >>= exact

λ> let x = head records
λ> toNode x >>= print
Node {nodeIdentity = 24, labels = ["Person"], nodeProps = fromList [("born",I 1962),("name",T "Tom Cruise")]}

To close connection just use:

λ> close pipe