Database.RethinkDB

Haskell client driver for RethinkDB

Based upon the official Javascript, Python and Ruby API: http://www.rethinkdb.com/api/

How to use

{-# LANGUAGE OverloadedStrings #-}
import qualified Database.RethinkDB as R
import qualified Database.RethinkDB.NoClash

Accessing RethinkDB

data RethinkDBHandle

A connection to the database server

Instances

Show RethinkDBHandle

connect :: HostName -> Integer -> Maybe String -> IO RethinkDBHandle

Create a new connection to the database server

Example: connect using the default port with no passphrase

>>> h <- connect "localhost" 28015 Nothing

close :: RethinkDBHandle -> IO ()

Close an open connection

use :: RethinkDBHandle -> Database -> RethinkDBHandle

Set the default database

The new handle is an alias for the old one. Calling close on either one will close both.

run :: (Expr query, Result r) => RethinkDBHandle -> query -> IO r

Run a given query and return a Result

run' :: Expr query => RethinkDBHandle -> query -> IO [JSON]

Run a given query and return a JSON

runOpts :: (Expr query, Result r) => RethinkDBHandle -> [RunOptions] -> query -> IO r

Run a query with the given options

next :: Cursor a -> IO (Maybe a)

Get the next value from a cursor

collect :: Cursor a -> IO [a]

A lazy stream of all the elements in the cursor

data RunOptions

Per-query settings

Constructors

UseOutdated

NoReply

SoftDurability Bool

data Cursor a

Instances

Functor Cursor

FromJSON a => Result (Cursor a)

data Response

The raw response to a query

Instances

Show Response

Result Response

class Result r where

Convert the raw query response into useful values

Methods

convertResult :: MVar Response -> IO r

Instances

Result Response

FromJSON a => Result [a]

FromJSON a => Result (Maybe a)

FromJSON a => Result (Cursor a)

data RethinkDBError

Constructors

RethinkDBError

Fields

errorCode :: ErrorCode

errorTerm :: BaseReQL

errorMessage :: String

errorBacktrace :: Backtrace

Instances

Show RethinkDBError

Exception RethinkDBError

Typeable * RethinkDBError

data SuccessCode

Constructors

SuccessPartial RethinkDBHandle Int64

Success

Instances

Show SuccessCode

data ErrorCode

Constructors

ErrorBrokenClient

ErrorBadQuery

ErrorRuntime

ErrorUnexpectedResponse

Instances

Show ErrorCode

data ReQL

An RQL term

Instances

Num ReQL

Show ReQL

IsString ReQL

Expr ReQL

((~) * a ReQL, (~) * b ReQL) => Expr (a -> b -> ReQL)

(~) * a ReQL => Expr (a -> ReQL)

data JSON

Constructors

JSON Value

Instances

Show JSON

FromJSON JSON

Manipulating databases

data Database

A database, referenced by name

Constructors

Database

Fields

databaseName :: Text

Instances

Eq Database

Ord Database

Show Database

Expr Database

db :: Text -> Database

Create a Database reference

>>> run' h $ db "test" # info
[{"name":"test","type":"DB"}]

dbCreate :: String -> ReQL

Create a database on the server

>>> run' h $ dbCreate "dev"
[{"created":1.0}]

dbDrop :: Database -> ReQL

Drop a database

>>> run' h $ dbDrop (db "dev")
[{"dropped":1.0}]

dbList :: ReQL

List the databases on the server

>>> run h $ dbList :: IO (Maybe [String])
Just ["test"]

Manipulating Tables

data Table

A table description

Constructors

Table

Fields

tableDatabase :: Maybe Database

when Nothing, use the connection's database

tableName :: Text

tablePrimaryKey :: Maybe Key

Instances

Eq Table

Ord Table

Show Table

Expr Table

data TableCreateOptions

Options used to create a table

Constructors

TableCreateOptions

Fields

tableDataCenter :: Maybe Text

tableCacheSize :: Maybe Int64

Instances

Default TableCreateOptions

data IndexCreateOptions

Options used to create an index

Constructors

IndexCreateOptions

Fields

indexMulti :: Maybe Bool

Instances

Default IndexCreateOptions

table :: Text -> Table

A table

>>> (mapM_ print =<<) $ run' h $ table "users"
{"post_count":0.0,"name":"nancy","id":"8d674d7a-873c-4c0f-8a4a-32a4bd5bdee8"}
{"post_count":1.0,"name":"bob","id":"b6a9df6a-b92c-46d1-ae43-1d2dd8ec293c"}
{"post_count":2.0,"name":"bill","id":"b2908215-1d3c-4ff5-b9ee-1a003fa9690c"}

tableCreate :: Table -> TableCreateOptions -> ReQL

Create a table on the server

>>> run' h $ tableCreate (table "posts") def
>>> run' h $ tableCreate (table "users") def
>>> run' h $ tableCreate (Table (db "prod") "bar" (Just "name")) def{ tableDataCenter = Just "cloud", tableCacheSize = Just 10 }

tableDrop :: Table -> ReQL

Drop a table

>>> run' h $ tableDrop (table "bar")
[{"dropped":1.0}]

tableList :: Database -> ReQL

List the tables in a database

>>> run h $ tableList (db "test") :: IO (Maybe [String])
Just ["foo","posts","users"]

indexCreate :: Expr fun => String -> fun -> IndexCreateOptions -> Table -> ReQL

Create an index on the table from the given function

>>> run' h $ table "users" # indexCreate "name" (!"name") def
[{"created":1.0}]

indexDrop :: Key -> Table -> ReQL

Drop an index

>>> run' h $ table "users" # indexDrop "name"
[{"dropped":1.0}]

indexList :: Table -> ReQL

List the indexes on the table

>>> run' h $ indexList (table "users")
[["name"]]

Writing data

data WriteResponse

Constructors

WriteResponse

Fields

writeResponseInserted :: Int

writeResponseDeleted :: Int

writeResponseReplaced :: Int

writeResponseUnchanged :: Int

writeResponseSkipped :: Int

writeResponseErrors :: Int

writeResponseFirstError :: Maybe Text

writeResponseGeneratedKeys :: Maybe [Text]

writeResponseOldVal :: Maybe Value

writeResponseNewVal :: Maybe Value

Instances

Show WriteResponse

FromJSON WriteResponse

insert :: Expr object => object -> Table -> ReQL

Insert a document or a list of documents into a table

>>> Just wr@WriteResponse{} <- run h $ table "users" # insert (map (\x -> obj ["name":=x]) ["bill", "bob", "nancy" :: Text])
>>> let Just [bill, bob, nancy] = writeResponseGeneratedKeys wr
>>> run' h $ table "posts" # insert (obj ["author" := bill, "message" := str "hi"])
>>> run' h $ table "posts" # insert (obj ["author" := bill, "message" := str "hello"])
>>> run' h $ table "posts" # insert (obj ["author" := bob, "message" := str "lorem ipsum"])

upsert :: (Expr table, Expr object) => object -> table -> ReQL

Like insert, but update existing documents with the same primary key

>>> run' h $ table "users" # upsert (obj ["id" := "79bfe377-9593-402a-ad47-f94c76c36a51", "name" := "rupert"])
[{"skipped":0.0,"inserted":0.0,"unchanged":0.0,"deleted":0.0,"replaced":1.0,"errors":0.0}]

update :: (Expr selection, Expr a) => (ReQL -> a) -> selection -> ReQL

Add to or modify the contents of a document

>>> run' h $ table "users" # getAll "name" [str "bob"] # update (const $ obj ["name" := str "benjamin"])
[{"skipped":0.0,"inserted":0.0,"unchanged":0.0,"deleted":0.0,"replaced":1.0,"errors":0.0}]

replace :: (Expr selection, Expr a) => (ReQL -> a) -> selection -> ReQL

Replace a document with another

>>> run' h $ replace (\bill -> obj ["name" := str "stoyan", "id" := bill!"id"]) . R.filter ((R.== str "bill") . (!"name")) $ table "users"
[{"skipped":0.0,"inserted":0.0,"unchanged":0.0,"deleted":0.0,"replaced":1.0,"errors":0.0}]

delete :: Expr selection => selection -> ReQL

Delete the documents

>>> run' h $ delete . getAll "name" [str "bob"] $ table "users"
[{"skipped":0.0,"inserted":0.0,"unchanged":0.0,"deleted":1.0,"replaced":0.0,"errors":0.0}]

returnVals :: ReQL -> ReQL

Include the value of single write operations in the returned object

nonAtomic :: ReQL -> ReQL

Allow non-atomic replace

Selecting data

data Bound a

An upper or lower bound for between and during

Constructors

Open

An inclusive bound

Fields

getBound :: a

Closed

An exclusive bound

Fields

getBound :: a

get :: Expr s => ReQL -> s -> ReQL

Get a document by primary key

>>> run' h $ table "users" # get "8d674d7a-873c-4c0f-8a4a-32a4bd5bdee8"
[{"post_count":0.0,"name":"nancy","id":"8d674d7a-873c-4c0f-8a4a-32a4bd5bdee8"}]

filter :: (Expr predicate, Expr seq) => predicate -> seq -> ReQL

Filter a sequence given a predicate

>>> run h $ R.filter (R.< 4) [3, 1, 4, 1, 5, 9, 2, 6] :: IO (Maybe [Int])
Just [3,1,1,2]

between :: (Expr left, Expr right, Expr seq) => Key -> Bound left -> Bound right -> seq -> ReQL

Query all the documents whose value for the given index is in a given range

>>> run h $ table "users" # between "id" (Closed $ str "a") (Open $ str "n") :: IO [JSON]
[{"post_count":4.0,"name":"bob","id":"b6a9df6a-b92c-46d1-ae43-1d2dd8ec293c"},{"post_count":4.0,"name":"bill","id":"b2908215-1d3c-4ff5-b9ee-1a003fa9690c"}]

getAll :: Expr value => Key -> [value] -> Table -> ReQL

Retreive documents by their indexed value

>>> run' h $ table "users" # getAll "name" ["bob"]
[{"post_count":1.0,"name":"bob","id":"b6a9df6a-b92c-46d1-ae43-1d2dd8ec293c"}]

Joins

innerJoin :: (Expr a, Expr b, Expr c) => (ReQL -> ReQL -> c) -> a -> b -> ReQL

SQL-like inner join of two sequences

>>> run' h $ innerJoin (\user post -> user!"id" R.== post!"author") (table "users") (table "posts") # mergeLeftRight # without ["id", "author"]
[[{"name":"bob","message":"lorem ipsum"},{"name":"bill","message":"hello"},{"name":"bill","message":"hi"}]]

outerJoin :: (Expr a, Expr b, Expr c) => (ReQL -> ReQL -> c) -> a -> b -> ReQL

SQL-like outer join of two sequences

>>> run' h $ outerJoin (\user post -> user!"id" R.== post!"author") (table "users") (table "posts") # mergeLeftRight # without ["id", "author"]
[[{"name":"nancy"},{"name":"bill","message":"hello"},{"name":"bill","message":"hi"},{"name":"bob","message":"lorem ipsum"}]]

eqJoin :: (Expr right, Expr left) => Key -> right -> Key -> left -> ReQL

An efficient inner_join that uses a key for the left table and an index for the right table.

>>> run' h $ table "posts" # eqJoin "author" (table "users") "id" # mergeLeftRight # without ["id", "author"]
[[{"name":"bill","message":"hi"},{"name":"bob","message":"lorem ipsum"},{"name":"bill","message":"hello"}]]

mergeLeftRight :: Expr a => a -> ReQL

Merge the "left" and "right" attributes of the objects in a sequence.

Called zip in the official drivers

>>> run' h $ table "posts" # eqJoin "author" (table "users") "id" # mergeLeftRight

Transformations

map :: (Expr a, Expr b) => (ReQL -> b) -> a -> ReQL

Map a function over a sequence

>>> run h $ R.map (!"a") [obj ["a" := 1], obj ["a" := 2]] :: IO (Maybe [Int])
Just [1,2]

withFields :: Expr seq => [ReQL] -> seq -> ReQL

Like hasFields followed by pluck

>>> run' h $ map obj [["a" := 1, "b" := 2], ["a" := 2, "c" := 7], ["b" := 4]] # withFields ["a"]
[[{"a":1.0},{"a":2.0}]]

concatMap :: (Expr a, Expr b) => (ReQL -> b) -> a -> ReQL

Map a function of a sequence and concat the results

>>> run h $ concatMap id [[1, 2], [3], [4, 5]] :: IO (Maybe [Int])
Just [1,2,3,4,5]

drop :: (Expr a, Expr b) => a -> b -> ReQL

Drop elements from the head of a sequence.

Called skip in the official drivers

>>> run h $ R.drop 2 [1, 2, 3, 4] :: IO (Maybe [Int])
Just [3,4]

take :: (Expr n, Expr seq) => n -> seq -> ReQL

Limit the size of a sequence.

Called limit in the official drivers

>>> run h $ R.take 2 [1, 2, 3, 4] :: IO (Maybe [Int])
Just [1,2]

(!!) :: Expr a => a -> ReQL -> ReQL infixl 9

Get the nth value of a sequence or array

>>> run h $ [1, 2, 3] !! 0 :: IO (Maybe Int)
Just 1

slice :: (Expr a, Expr b, Expr c) => a -> b -> c -> ReQL

Cut out part of a sequence

>>> run h $ slice 2 4 [1, 2, 3, 4, 5] :: IO (Maybe [Int])
Just [3,4]

orderBy :: Expr s => [Order] -> s -> ReQL

Order a sequence by the given keys

>>> run' h $ table "users" # orderBy [Desc "post_count", Asc "name"] # pluck ["name", "post_count"]
[[{"post_count":2.0,"name":"bill"},{"post_count":1.0,"name":"bob"},{"name":"nancy"}]]

data Order

Ordering specification for orderBy

Constructors

Asc

Ascending order

Fields

orderAttr :: Key

Desc

Descending order

Fields

orderAttr :: Key

indexesOf :: (Expr fun, Expr seq) => fun -> seq -> ReQL

The position in the sequence of the elements that match the predicate

>>> run h $ indexesOf (=~ "ba.") [str "foo", "bar", "baz"] :: IO (Maybe [Int])
Just [1,2]

isEmpty :: Expr seq => seq -> ReQL

Test if a sequence is empty

>>> run h $ isEmpty [1] :: IO (Maybe Bool)
Just False

(++) :: (Expr a, Expr b) => a -> b -> ReQL infixr 5

Join two sequences.

Called union in the official drivers

>>> run h $ [1,2,3] R.++ ["a", "b", "c" :: Text] :: IO (Maybe [JSON])
Just [1.0,2.0,3.0,"a","b","c"]

sample :: (Expr n, Expr seq) => n -> seq -> ReQL

Select a given number of elements from a sequence with uniform random distribution

>>> run h $ sample 3 [0,1,2,3,4,5,6,7,8,9] :: IO (Maybe [Int])
Just [4,3,8]

Aggregation

reduce :: (Expr base, Expr seq, Expr a) => (ReQL -> ReQL -> a) -> base -> seq -> ReQL

Reduce a sequence to a single value

>>> run h $ reduce (+) 0 [1, 2, 3] :: IO (Maybe Int)
Just 6

reduce1 :: (Expr a, Expr s) => (ReQL -> ReQL -> a) -> s -> ReQL

Reduce a non-empty sequence to a single value

>>> run h $ reduce1 (+) [1, 2, 3] :: IO (Maybe Int)
Just 6

nub :: Expr s => s -> ReQL

Filter out identical elements of the sequence

Called distint in the official drivers

>>> run h $ nub (table "posts" ! "flag") :: IO (Maybe [String])
Just ["pinned", "deleted"]

groupBy :: (Expr group, Expr reduction, Expr seq) => (ReQL -> group) -> (ReQL -> reduction) -> seq -> ReQL

Turn a grouping function and a reduction function into a grouped map reduce operation

>>> run' h $ table "posts" # groupBy (!"author") (reduce1 (\a b -> a + "\n" + b) . R.map (!"message"))
[[{"group":"b2908215-1d3c-4ff5-b9ee-1a003fa9690c","reduction":"hi\nhello"},{"group":"b6a9df6a-b92c-46d1-ae43-1d2dd8ec293c","reduction":"lorem ipsum"}]]
>>> run' h $ table "users" # groupBy (!"level") (\users -> let pc = users!"post_count" in [avg pc, R.sum pc])
[[{"group":1,"reduction":[1.5,3.0]},{"group":2,"reduction":[0.0,0.0]}]]

elem :: (Expr x, Expr seq) => x -> seq -> ReQL

Test if a sequence contains a given element

>>> run' h $ 1 `R.elem` [1,2,3]
[true]

Aggregators

length :: Expr a => a -> ReQL

The size of a sequence or an array.

Called count in the official drivers

>>> run h $ R.length (table "foo") :: IO (Maybe Int)
Just 17

sum :: Expr s => s -> ReQL

The sum of a sequence

>>> run h $ sum [1, 2, 3] :: IO (Maybe Int)
Just 6

avg :: Expr s => s -> ReQL

The average of a sequence

>>> run h $ avg [1, 2, 3, 4] :: IO (Maybe Double)
Just 2.5

Document manipulation

pluck :: Expr o => [ReQL] -> o -> ReQL

Keep only the given attributes

>>> run' h $ map obj [["a" := 1, "b" := 2], ["a" := 2, "c" := 7], ["b" := 4]] # pluck ["a"]
[[{"a":1.0},{"a":2.0},{}]]

without :: Expr o => [ReQL] -> o -> ReQL

Remove the given attributes from an object

>>> run' h $ map obj [["a" := 1, "b" := 2], ["a" := 2, "c" := 7], ["b" := 4]] # without ["a"]
[[{"b":2.0},{"c":7.0},{"b":4.0}]]

merge :: (Expr a, Expr b) => a -> b -> ReQL

Merge two objects together

>>> run' h $ merge (obj ["a" := 1, "b" := 1]) (obj ["b" := 2, "c" := 2])
[{"a":1.0,"b":2.0,"c":2.0}]

append :: (Expr a, Expr b) => a -> b -> ReQL

Append a datum to a sequence

>>> run h $ append 3 [1, 2] :: IO (Maybe [Int])
Just [1,2,3]

prepend :: (Expr datum, Expr array) => datum -> array -> ReQL

Prepend an element to an array

>>> run h $ prepend 1 [2,3] :: IO (Maybe [Int])
Just [1,2,3]

(\\) :: (Expr a, Expr b) => a -> b -> ReQL infixl 9

Called difference in the official drivers

>>> run h $ [1,2,3,4,5] \\ [2,5] :: IO (Maybe [Int])
Just [1,3,4]

setInsert :: (Expr datum, Expr array) => datum -> array -> ReQL

Insert a datum into an array if it is not yet present

>>> run h $ setInsert 3 [1,2,4,4,5] :: IO (Maybe [Int])
Just [1,2,4,5,3]

setUnion :: (Expr a, Expr b) => a -> b -> ReQL

The union of two sets

>>> run h $ [1,2] `setUnion` [2,3]  :: IO (Maybe [Int])
Just [2,3,1]

setIntersection :: (Expr a, Expr b) => a -> b -> ReQL

The intersection of two sets

>>> run h $ [1,2] `setIntersection` [2,3]  :: IO (Maybe [Int])
Just [2]

setDifference :: (Expr set, Expr remove) => remove -> set -> ReQL

The difference of two sets

>>> run h $ [2,3] # setDifference [1,2]  :: IO (Maybe [Int])
Just [3]

(!) :: Expr s => s -> ReQL -> ReQL infixl 9

Get a single field from an object

>>> run h $ (obj ["foo" := True]) ! "foo" :: IO (Maybe Bool)
Just True

Or a single field from each object in a sequence

>>> run h $ [obj ["foo" := True], obj ["foo" := False]] ! "foo" :: IO (Maybe [Bool])
Just [True,False]

hasFields :: Expr obj => ReQL -> obj -> ReQL

Test if an object has the given fields

>>> run h $ hasFields ["a"] $ obj ["a" := 1] :: IO (Maybe Bool)
Just True

insertAt :: (Expr n, Expr datum, Expr array) => n -> datum -> array -> ReQL

Insert a datum at the given position in an array

>>> run h $ insertAt 1 4 [1,2,3] :: IO (Maybe [Int])
Just [1,4,2,3]

spliceAt :: (Expr n, Expr replace, Expr array) => n -> replace -> array -> ReQL

Splice an array at a given position inside another array

>>> run h $ spliceAt 2 [4,5] [1,2,3] :: IO (Maybe [Int])
Just [1,2,4,5,3]

deleteAt :: (Expr n, Expr array) => n -> array -> ReQL

Delete an element from an array

>>> run h $ deleteAt 1 [1,2,3] :: IO (Maybe [Int])
Just [1,3]

changeAt :: (Expr n, Expr datum, Expr array) => n -> datum -> array -> ReQL

Change an element in an array

>>> run h $ changeAt 1 4 [1,2,3] :: IO (Maybe [Int])
Just [1,4,3]

keys :: Expr obj => obj -> ReQL

The list of keys of the given object

>>> run h $ keys (obj ["a" := 1, "b" := 2]) :: IO (Maybe [String])
Just ["a","b"]

Math and logic

(+) :: (Expr a, Expr b) => a -> b -> ReQL infixl 6

Addition or concatenation

Use the Num instance, or a qualified operator.

>>> run h $ 2 + 5 :: IO (Maybe Int)
Just 7
>>> run h $ 2 R.+ 5 :: IO (Maybe Int)
Just 7
>>> run h $ (str "foo") + (str "bar") :: IO (Just String)
Just "foobar"

(-) :: (Expr a, Expr b) => a -> b -> ReQL infixl 6

Subtraction

>>> run h $ 2 - 5 :: IO (Maybe Int)
Just (-3)

(*) :: (Expr a, Expr b) => a -> b -> ReQL infixl 7

Multiplication

>>> run h $ 2 * 5 :: IO (Maybe Int)
Just 10

(/) :: (Expr a, Expr b) => a -> b -> ReQL infixl 7

Division

>>> run h $ 2 R./ 5 :: IO (Maybe Double)
Just 0.4

mod :: (Expr a, Expr b) => a -> b -> ReQL

Mod

>>> run h $ 5 `mod` 2 :: IO (Maybe Int)
Just 1

(&&) :: (Expr a, Expr b) => a -> b -> ReQL infixr 3

Boolean and

>>> run h $ True R.&& False :: IO (Maybe Bool)
Just False

(||) :: (Expr a, Expr b) => a -> b -> ReQL infixr 2

Boolean or

>>> run h $ True R.|| False :: IO (Maybe Bool)
Just True

(==) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Test for equality

>>> run h $ obj ["a" := 1] R.== obj ["a" := 1] :: IO (Maybe Bool)
Just True

(/=) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Test for inequality

>>> run h $ 1 R./= False :: IO (Maybe Bool)
Just True

(>) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Greater than

>>> run h $ 3 R.> 2 :: IO (Maybe Bool)
Just True

(<) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Lesser than

>>> run h $ (str "a") R.< (str "b") :: IO (Maybe Bool)
Just True

(<=) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Lesser than or equal to

>>> run h $ 2 R.<= 2 :: IO (Maybe Bool)
Just True

(>=) :: (Expr a, Expr b) => a -> b -> ReQL infix 4

Greater than or equal to

>>> run h $ [1] R.>= () :: IO (Maybe Bool)
Just False

not :: Expr a => a -> ReQL

Negation

>>> run h $ R.not False :: IO (Maybe Bool)
Just True
>>> run h $ R.not () :: IO (Maybe Bool)
Just True

String manipulation

(=~) :: Expr string => string -> ReQL -> ReQL

Match a string to a regular expression.

Called match in the official drivers

>>> run' h $ str "foobar" =~ "f(.)+[bc](.+)"
[{"groups":[{"start":2.0,"end":3.0,"str":"o"},{"start":4.0,"end":6.0,"str":"ar"}],"start":0.0,"end":6.0,"str":"foobar"}]

Dates and times

newtype UTCTime

Time with no time zone

The default FromJSON instance for Data.Time.UTCTime is incompatible with ReQL's time type

Constructors

UTCTime UTCTime

Instances

Show UTCTime

ToJSON UTCTime

FromJSON UTCTime

Expr UTCTime

newtype ZonedTime

Time with a time zone

The default FromJSON instance for Data.Time.ZonedTime is incompatible with ReQL's time type

Constructors

ZonedTime ZonedTime

Instances

Show ZonedTime

ToJSON ZonedTime

FromJSON ZonedTime

Expr ZonedTime

now :: ReQL

The time and date when the query is executed

>>> run h $ now :: IO (Maybe R.ZonedTime)
Just 2013-10-28 00:01:43.930000066757 +0000

time :: ReQL -> ReQL -> ReQL -> ReQL -> ReQL -> ReQL -> ReQL -> ReQL

Build a time object from the year, month, day, hour, minute, second and timezone fields

>>> run h $ time 2011 12 24 23 59 59 "Z" :: IO (Maybe R.ZonedTime)
Just 2011-12-24 23:59:59 +0000

epochTime :: ReQL -> ReQL

Build a time object given the number of seconds since the unix epoch

>>> run h $ epochTime 1147162826 :: IO (Maybe R.ZonedTime)
Just 2006-05-09 08:20:26 +0000

iso8601 :: ReQL -> ReQL

Build a time object given an iso8601 string

>>> run h $ iso8601 "2012-01-07T08:34:00-0700" :: IO (Maybe R.UTCTime)
Just 2012-01-07 15:34:00 UTC

inTimezone :: Expr time => ReQL -> time -> ReQL

The same time in a different timezone

>>> run h $ inTimezone "+0800" now :: IO (Maybe R.ZonedTime)
Just 2013-10-28 08:16:39.22000002861 +0800

during :: (Expr left, Expr right, Expr time) => Bound left -> Bound right -> time -> ReQL

Test if a time is between two other times

>>> run h $ during (Open $ now - (60*60)) (Closed now) $ epochTime 1382919271 :: IO (Maybe Bool)
Just True

timezone :: Expr time => time -> ReQL

Extract part of a time value

date :: Expr time => time -> ReQL

Extract part of a time value

timeOfDay :: Expr time => time -> ReQL

Extract part of a time value

year :: Expr time => time -> ReQL

Extract part of a time value

month :: Expr time => time -> ReQL

Extract part of a time value

day :: Expr time => time -> ReQL

Extract part of a time value

dayOfWeek :: Expr time => time -> ReQL

Extract part of a time value

dayOfYear :: Expr time => time -> ReQL

Extract part of a time value

hours :: Expr time => time -> ReQL

Extract part of a time value

minutes :: Expr time => time -> ReQL

Extract part of a time value

seconds :: Expr time => time -> ReQL

Extract part of a time value

toIso8601 :: Expr t => t -> ReQL

Convert a time to another representation

toEpochTime :: Expr t => t -> ReQL

Convert a time to another representation

Control structures

apply :: (Expr fun, Expr arg) => fun -> [arg] -> ReQL

Apply a function to a list of arguments.

Called do in the official drivers

>>> run h $ (\x -> x R.* 2) `apply` [4] :: IO (Maybe Int)
Just 8

js :: ReQL -> ReQL

Evaluate a JavaScript expression

>>> run h $ js "Math.random()" :: IO (Maybe Double)
Just 0.9119815775193274
>>> run h $ R.map (\x -> js "Math.sin" `apply` [x]) [pi, pi/2] :: IO (Maybe [Double])
Just [1.2246063538223773e-16,1.0]

if' :: (Expr a, Expr b, Expr c) => a -> b -> c -> ReQL

Called branch in the official drivers

>>> run h $ if' (1 R.< 2) 3 4 :: IO (Maybe Int)
Just 3

forEach :: (Expr s, Expr a) => s -> (ReQL -> a) -> ReQL

Like map but for write queries

>>> run' h $ table "users" # replace (without ["post_count"])
>>> run' h $ forEach (table "posts") $ \post -> table "users" # get (post!"author") # update (\user -> obj ["post_count" := (handle 0 (user!"post_count") + 1)])
[{"skipped":0.0,"inserted":0.0,"unchanged":0.0,"deleted":0.0,"replaced":3.0,"errors":0.0}]

error :: Expr s => s -> ReQL

Abort the query with an error

>>> run' h $ R.error (str "haha") R./ 2 + 1
*** Exception: RethinkDBError {errorCode = runtime error, errorTerm = ADD(DIV(ERROR("haha"), 2.0), 1.0), errorMessage = "haha", errorBacktrace = [0,0]}

handle :: (Expr handler, Expr reql) => handler -> reql -> ReQL

Catch some expections inside the query.

Called default in the official drivers

>>> run h $ handle 0 $ obj ["a" := 1] ! "b" :: IO (Maybe Int)
Just 0
>>> run h $ handle (expr . id) $ obj ["a" := 1] ! "b" :: IO (Maybe String)
Just "No attribute `b` in object:\n{\n\t\"a\":\t1\n}"

class Expr e where

Convert other types into ReqL expressions

Methods

expr :: e -> ReQL

Instances

Expr Bool

Expr Double

Expr Int

Expr Int64

Expr Integer

Expr Rational

Expr ()

Expr Text

Expr UTCTime

Expr Value

Expr ZonedTime

Expr Datum

Expr Table

Expr Database

Expr Object

Expr BaseReQL

Expr ReQL

Expr ZonedTime

Expr UTCTime

Expr a => Expr [a]

Expr x => Expr (Vector x)

((~) * a ReQL, (~) * b ReQL) => Expr (a -> b -> ReQL)

(~) * a ReQL => Expr (a -> ReQL)

(Expr a, Expr b) => Expr (a, b)

Expr e => Expr (HashMap Text e)

(Expr a, Expr b, Expr c) => Expr (a, b, c)

(Expr a, Expr b, Expr c, Expr d) => Expr (a, b, c, d)

(Expr a, Expr b, Expr c, Expr d, Expr e) => Expr (a, b, c, d, e)

coerceTo :: Expr x => ReQL -> x -> ReQL

Convert a value to a different type

>>> run h $ coerceTo "STRING" 1 :: IO (Maybe String)
Just "1"

asArray :: Expr x => x -> ReQL

Convert a value to an array

>>> run h $ asArray $ obj ["a" := 1, "b" := 2] :: IO (Maybe [(String, Int)])
Just [("a",1),("b",2)]

asString :: Expr x => x -> ReQL

Convert a value to a string

>>> run h $ asString $ obj ["a" := 1, "b" := 2] :: IO (Maybe String)
Just "{\n\t\"a\":\t1,\n\t\"b\":\t2\n}"

asNumber :: Expr x => x -> ReQL

Convert a value to a number

>>> run h $ asNumber (str "34") :: IO (Maybe Int)
Just 34

asObject :: Expr x => x -> ReQL

Convert a value to an object

>>> run' h $ asObject $ [(str "a",1),("b",2)]
[{"a":1.0,"b":2.0}]

asBool :: Expr x => x -> ReQL

Convert a value to a boolean

typeOf :: Expr a => a -> ReQL

A string representing the type of an expression

>>> run h $ typeOf 1 :: IO (Maybe String)
Just "NUMBER"

info :: Expr a => a -> ReQL

Get information on a given expression. Useful for tables and databases.

>>> run' h $ info $ table "foo"
[{"primary_key":"id","name":"foo","indexes":[],"type":"TABLE","db":{"name":"test","type":"DB"}}]

json :: ReQL -> ReQL

Parse a json string into an object

>>> run' h $ json "{a:1}"
[{"a":1.0}]

Helpers

class Obj o where

Convert into a ReQL object

Methods

obj :: o -> Object

Instances

Obj ()

Obj Object

Obj [BaseAttribute]

Obj [Attribute]

data Object

A list of key/value pairs

Instances

Obj Object

Expr Object

data Attribute

A key/value pair used for building objects

Constructors

forall e . Expr e => Text := e infix 0

Instances

Obj [Attribute]

str :: String -> ReQL

A shortcut for inserting strings into ReQL expressions Useful when OverloadedStrings makes the type ambiguous

num :: Double -> ReQL

A shortcut for inserting numbers into ReQL expressions

(.) :: (Expr a, Expr b, Expr c) => (ReQL -> b) -> (ReQL -> a) -> c -> ReQL infixr 9

Specialised function composition

(#) :: (Expr a, Expr b) => a -> (a -> b) -> ReQL infixl 8

Flipped function application

def :: Default a => a

The default value for this type.