rethinkdb-1.15.1.0: A driver for RethinkDB 1.15

Safe HaskellNone

Database.RethinkDB

Contents

Description

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

Synopsis

Accessing RethinkDB

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

data RethinkDBHandle

A connection to the database server

Instances

close :: RethinkDBHandle -> IO ()

Close an open connection

use :: Database -> RethinkDBHandle -> 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 h $ num 1 :: IO Int
1

>>> run h $ str "foo" :: IO (Either RethinkDBError Int)
Left RethinkDB: Unexpected response: "when expecting a Int, encountered String instead"

>>> run h $ str "foo" :: IO (Maybe Int)
Nothing

>>> run h $ str "foo" :: IO Int
*** Exception: RethinkDB: Unexpected response: "when expecting a Int, encountered String instead"

>>> c <- run h $ table "users" # orderBy [asc "name"] # (!"name"):: IO (Cursor Datum)
>>> next c
Just "bill"
>>> collect c
["nancy","sabrina"]

run' :: Expr query => RethinkDBHandle -> query -> IO Datum

Run a given query and return a Datum

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

Run a query with the given options

data ReQL

A ReQL Term

Instances

Floating ReQL 
Fractional ReQL 
Num ReQL 
Show ReQL 
IsString ReQL 
Expr ReQL 
OptArgs ReQL 
(~ * a ReQL, ~ * b ReQL) => Expr (a -> b -> ReQL) 
~ * a ReQL => Expr (a -> ReQL) 

data Datum

A ReQL value

Constructors

Null 
Bool Bool 
String Text 
Number Double 
Array Array 
Object Object 
Time ZonedTime 
Point LonLat 
Line Line 
Polygon Polygon 
Binary ByteString 

Instances

class ToDatum a where

Methods

toDatum :: a -> Datum

Instances

class FromDatum a where

Methods

parseDatum :: Datum -> Parser a

Instances

fromDatum :: FromDatum a => Datum -> Result a

data RunFlag

Per-query settings

Constructors

UseOutdated 
NoReply 
Durability Durability 
Profile 
ArrayLimit Int 

noReplyWait :: RethinkDBHandle -> IO ()

Wait for NoReply queries to complete on the server 

>>> () <- runOpts h [NoReply] $ table "users" # get "bob" # update (\row -> merge row ["occupation" := "teacher"])
>>> noReplyWait h

data RethinkDBError

Constructors

RethinkDBError 

Fields

errorCode :: ErrorCode
 
errorTerm :: Term
 
errorMessage :: String
 
errorBacktrace :: Backtrace
 

Instances

data ErrorCode

Constructors

ErrorBrokenClient 
ErrorBadQuery 
ErrorRuntime 
ErrorUnexpectedResponse 

Instances

data Response

The response to a query

Instances

class Result r where

Convert the raw query response into useful values

Methods

convertResult :: MVar Response -> IO r

Instances

Cursors

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

collect' :: Cursor a -> IO [a]

A strict version of collect

each :: Cursor a -> (a -> IO b) -> IO ()

data Cursor a

Instances

Manipulating databases

data Database

A database, referenced by name

Constructors

Database 

Fields

databaseName :: Text
 

Instances

dbCreate :: String -> ReQL

Create a database on the server 

>>> run' h $ dbCreate "dev"
{"created":1}

dbDrop :: Database -> ReQL

Drop a database 

>>> run' h $ dbDrop (db "dev")
{"dropped":1}

dbList :: ReQL

List the databases on the server 

>>> _ <- run' h $ dbList

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

tableCreate :: Table -> ReQL

Create a table on the server 

 >>> run' h $ tableCreate (table "posts") def
 [{"created":1}]
 >>> run' h $ tableCreate (table "users"){ tablePrimaryKey = Just "name" } def
 [{"created":1}]
 >>> run' h $ tableCreate (Table (Just "doctests") "bar" (Just "name")) def
 [{"created":1}]
 >>> run' h $ ex tableCreate ["datacenter":="orion"] (Table (Just "doctests") "bar" (Just "name")) def
 [{"created":1}]

tableDrop :: Table -> ReQL

Drop a table 

>>> run' h $ tableDrop (table "foo")
{"dropped":1}

tableList :: Database -> ReQL

List the tables in a database 

>>> fmap sort $ run h $ tableList (db "doctests") :: IO [String]
["places","posts","users"]

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

Create an index on the table from the given function 

>>> run' h $ table "users" # indexCreate "occupation" (!"occupation")
{"created":1}
>>> run' h $ table "users" # ex indexCreate ["multi":=True] "friends" (!"friends")
{"created":1}
>>> run' h $ table "users" # ex indexCreate ["geo":=True] "location" (!"location")
{"created":1}

indexDrop :: Key -> Table -> ReQL

Drop an index 

>>> run' h $ table "users" # indexDrop "occupation"
{"dropped":1}

indexList :: Table -> ReQL

List the indexes on the table 

>>> run' h $ indexList (table "users")
["friends","location","occupation"]

indexRename :: Expr table => ReQL -> ReQL -> table -> ReQL

indexStatus :: Expr table => [ReQL] -> table -> ReQL

Get the status of the given indexes 

 run' h $ table "users" # indexStatus []

indexWait :: Expr table => [ReQL] -> table -> ReQL

Wait for an index to be built 

 run' h $ table "users" # indexWait []

changes :: Expr seq => seq -> ReQL

Return an infinite stream of objects representing changes to a table 

>>> cursor <- run h $ table "posts" # changes :: IO (Cursor Datum)
>>> run h $ table "posts" # insert ["author" := "bill", "message" := "bye", "id" := 4] :: IO WriteResponse
{inserted:1}
>>> next cursor
Just {"new_val":{"author":"bill","id":4,"message":"bye"},"old_val":null}

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]
 
writeResponseChanges :: Maybe [Change]
 

Instances

data Change

Constructors

Change 

Fields

oldVal :: Datum
 
newVal :: Datum
 

Instances

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

Insert a document or a list of documents into a table 

>>> run h $ table "users" # insert (map (\x -> ["name":=x]) ["bill", "bob", "nancy" :: Text]) :: IO WriteResponse
{inserted:3}
>>> run h $ table "posts" # insert ["author" := str "bill", "message" := str "hi", "id" := 1] :: IO WriteResponse
{inserted:1}
>>> run h $ table "posts" # insert ["author" := str "bill", "message" := str "hello", "id" := 2, "flag" := str "deleted"] :: IO WriteResponse
{inserted:1}
>>> run h $ table "posts" # insert ["author" := str "bob", "message" := str "lorem ipsum", "id" := 3, "flag" := str "pinned"] :: IO WriteResponse
{inserted:1}

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 ["occupation" := str "tailor"]) :: IO WriteResponse
{replaced:1}

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

Replace a document with another 

>>> run h $ replace (\user -> ["name" := user!"name", "occupation" := str "clothier"]) . R.filter ((R.== str "tailor") . (!?"occupation")) $ table "users" :: IO WriteResponse
{replaced:1}

delete :: Expr selection => selection -> ReQL

Delete the documents 

>>> run h $ delete . getAll "name" [str "bob"] $ table "users" :: IO WriteResponse
{deleted:1}

sync :: Expr table => table -> ReQL

Ensures that writes on a given table are written to permanent storage 

>>> run' h $ sync (table "users")
{"synced":1}

returnChanges :: Attribute a

Optional argument for returning an array of objects describing the changes made 

>>> run h $ table "users" # ex insert [returnChanges] ["name" := "sabrina"] :: IO WriteResponse
{inserted:1,changes:[{"old_val":null,"new_val":{"name":"sabrina"}}]}

nonAtomic :: Attribute a

Optional argument for non-atomic writes 

>>> run' h $ table "users" # get "sabrina" # update (merge ["lucky_number" := random])
*** Exception: RethinkDB: Runtime error: "Could not prove function deterministic.  Maybe you want to use the non_atomic flag?"
  in
    {- HERE -}
    update(
      get(table(db("doctests"), "users"), "sabrina"),
      (\b -> merge(b, {lucky_number: random()})))
>>> run h $ table "users" # get "sabrina" # ex update [nonAtomic] (merge ["lucky_number" := random]) :: IO WriteResponse
{replaced:1}

durability :: Durability -> Attribute a

Optional argument for soft durability writes

data Durability

Instances

conflict :: ConflictResolution -> Attribute a

data ConflictResolution

Constructors

Error 
Replace 
Update 

Instances

Selecting data

db :: Text -> Database

Create a Database reference 

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

table :: Text -> Table

A table 

>>> fmap sort $ run h $ table "users" :: IO [Datum]
[{"post_count":2,"name":"bill"},{"post_count":0,"name":"nancy"}]

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

Get a document by primary key 

>>> run' h $ table "users" # get "nancy"
{"post_count":0,"name":"nancy"}

getAll :: Expr values => Index -> values -> Table -> ReQL

Retreive documents by their indexed value 

>>> run' h $ table "users" # getAll PrimaryKey [str "bill"]
[{"post_count":2,"name":"bill"}]

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]
[3,1,1,2]

between :: (Expr left, Expr right, Expr seq) => Index -> 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 "name" (Closed $ str "a") (Open $ str "c")
[{"post_count":2,"name":"bill"}]

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
 
DefaultBound 

Fields

getBound :: a
 

Instances

Functor Bound 
Num a => Num (Bound a) 

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!"name" R.== post!"author") (table "users") (table "posts") # R.zip # orderBy [asc "id"] # pluck ["name", "message"]
[{"name":"bill","message":"hi"},{"name":"bill","message":"hello"}]

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!"name" R.== post!"author") (table "users") (table "posts") # R.zip # orderBy [asc "id", asc "name"] # pluck ["name", "message"]
[{"name":"nancy"},{"name":"bill","message":"hi"},{"name":"bill","message":"hello"}]

eqJoin :: (Expr fun, Expr right, Expr left) => fun -> right -> Index -> 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") "name" # R.zip # orderBy [asc "id"] # pluck ["name", "message"]
[{"name":"bill","message":"hi"},{"name":"bill","message":"hello"}]

zip :: Expr a => a -> ReQL

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

>>> fmap sort $ run h $ table "posts" # eqJoin "author" (table "users") "name" # R.zip :: IO [Datum]
[{"post_count":2,"flag":"deleted","name":"bill","author":"bill","id":2,"message":"hello"},{"post_count":2,"name":"bill","author":"bill","id":1,"message":"hi"}]

data Index

Constructors

PrimaryKey 
Index Key 

Instances

Transformations

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

Map a function over a sequence 

>>> run h $ R.map (!"a") [["a" := 1], ["a" := 2]]
[1,2]

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

Like hasFields followed by pluck 

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

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]]
[1,2,3,4,5]

orderBy :: Expr s => [ReQL] -> 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,"name":"bill"},{"post_count":0,"name":"nancy"}]

>>> run' h $ table "users" # ex orderBy ["index":="name"] [] # pluck ["name"]
[{"name":"bill"},{"name":"nancy"}]

asc :: ReQL -> ReQL

Ascending order

desc :: ReQL -> ReQL

Descending order

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

Drop elements from the head of a sequence. 

>>> run h $ skip 2 [1, 2, 3, 4]
[3,4]

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

Limit the size of a sequence. 

>>> run h $ limit 2 [1, 2, 3, 4]
[1,2]

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]
[3,4]

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

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

>>> run h $ indexesOf (match "ba.") [str "foo", "bar", "baz"]
[1,2]

isEmpty :: Expr seq => seq -> ReQL

Test if a sequence is empty 

>>> run h $ isEmpty [1]
false

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

Join two sequences. 

>>> run h $ [1,2,3] `union` ["a", "b", "c" :: Text]
[1,2,3,"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]

Aggregation

group :: (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" # group (!"author") (reduce (\a b -> a + "\n" + b) . R.map (!"message"))
[{"group":"bill","reduction":"hi\nhello"},{"group":"bob","reduction":"lorem ipsum"}]
>>> run' h $ table "users" # group ((!0) . splitOn "" . (!"name")) (\users -> let pc = users!"post_count" in [avg pc, R.sum pc])
[{"group":"b","reduction":[2,2]},{"group":"n","reduction":[0,0]}]

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

Reduce a non-empty sequence to a single value 

>>> run h $ reduce (+) [1, 2, 3]
6

reduce0 :: (Expr base, Expr seq, Expr a) => (ReQL -> ReQL -> a) -> base -> seq -> ReQL

Reduce a sequence to a single value 

>>> run h $ reduce0 (+) 0 [1, 2, 3]
6

distinct :: Expr s => s -> ReQL

Filter out identical elements of the sequence 

>>> fmap sort $ run h $ distinct (table "posts" ! "flag") :: IO [String]
["deleted","pinned"]

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

Test if a sequence contains a given element 

>>> run' h $ [1,2,3] # contains 1
true

mapReduce :: (Expr reduction, Expr seq) => (ReQL -> reduction) -> seq -> ReQL

Rewrite multiple reductions into a single map/reduce operation

Aggregators

count :: Expr a => a -> ReQL

The size of a sequence or an array. 

>>> run h $ count (table "users")
2

sum :: Expr s => s -> ReQL

The sum of a sequence 

>>> run h $ sum [1, 2, 3]
6

avg :: Expr s => s -> ReQL

The average of a sequence 

>>> run h $ avg [1, 2, 3, 4]
2.5

min :: Expr s => s -> ReQL

Minimum value

max :: Expr s => s -> ReQL

Minimum value

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

Value that minimizes the function

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

Value that maximizes the function

Document manipulation

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

Keep only the given attributes 

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

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

Remove the given attributes from an object 

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

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

Merge two objects together 

>>> run' h $ merge ["a" := 1, "b" := 1] ["b" := 1, "c" := 2]
{"a":1,"b":1,"c":2}

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

Append a datum to a sequence 

>>> run h $ append 3 [1, 2]
[1,2,3]

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

Prepend an element to an array 

>>> run h $ prepend 1 [2,3]
[1,2,3]

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

The different of two lists 

>>> run h $ [1,2,3,4,5] # difference [2,5]
[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]
[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]
[2,3,1]

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

The intersection of two sets 

>>> run h $ [1,2] `setIntersection` [2,3]
[2]

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

The difference of two sets 

>>> run h $ [2,3] # setDifference [1,2]
[3]

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

Get a single field from an object or an element of an array 

>>> run h $ ["foo" := True] ! "foo"
true

>>> run h $ [1, 2, 3] ! 0
1

Or a single field from each object in a sequence 

>>> run h $ [["foo" := True], ["foo" := False]] ! "foo"
[true,false]

(!?) :: Expr s => s -> ReQL -> ReQL

Get a single field, or null if not present 

>>> run' h $ empty !? "foo"
null

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

Test if an object has the given fields 

>>> run h $ hasFields "a" $ ["a" := 1]
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]
[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]
[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]
[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]
[1,4,3]

keys :: Expr object => object -> ReQL

The list of keys of the given object 

>>> run h $ keys ["a" := 1, "b" := 2]
["a","b"]

literal :: Expr a => a -> ReQL

Literal objects, in a merge or update, are not processed recursively. 

>>> run' h $ ["a" := ["b" := 1]] # merge ["a" := literal ["c" := 2]]
{"a":{"c":2}}

remove :: ReQL

Remove fields when doing a merge or update 

>>> run' h $ ["a" := ["b" := 1]] # merge ["a" := remove]
{}

data Attribute a where

A key/value pair used for building objects

Constructors

:= :: Expr e => Text -> e -> Attribute a 
::= :: (Expr k, Expr v) => k -> v -> Attribute Dynamic 
NoAttribute :: Attribute a 

Instances

String manipulation

match :: Expr string => ReQL -> string -> ReQL

Match a string to a regular expression. 

>>> run' h $ str "foobar" # match "f(.)+[bc](.+)"
{"groups":[{"start":2,"end":3,"str":"o"},{"start":4,"end":6,"str":"ar"}],"start":0,"end":6,"str":"foobar"}

upcase :: Expr str => str -> ReQL

Convert to upper case 

>>> run h $ upcase (str "Foo")
"FOO"

downcase :: Expr str => str -> ReQL

Convert to lower case 

>>> run h $ downcase (str "Foo")
"foo"

split :: Expr str => str -> ReQL

Split a string on whitespace characters 

>>> run' h $ split (str "foo bar")
["foo","bar"]

splitOn :: Expr str => ReQL -> str -> ReQL

Split a string on a given delimiter 

>>> run' h $ str "foo, bar" # splitOn ","
["foo"," bar"]

>>> run' h $ str "foo" # splitOn ""
["f","o","o"]

splitMax :: Expr str => ReQL -> ReQL -> str -> ReQL

Split a string up to a given number of times 

>>> run' h $ str "a:b:c:d" # splitMax ":" 2
["a","b","c:d"]

Math and logic

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

Addition or concatenation

Use the Num instance, or a qualified operator. 

>>> run h $ 2 + 5
7
>>> run h $ str "foo" R.+ str "bar"
"foobar"

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

Subtraction 

>>> run h $ 2 - 5
-3

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

Multiplication 

>>> run h $ 2 * 5
10

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

Division 

>>> run h $ 2 R./ 5
0.4

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

Mod 

>>> run h $ 5 `mod` 2
1

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

Boolean and 

>>> run h $ True R.&& False
false

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

Boolean or 

>>> run h $ True R.|| False
true

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

Test for equality 

>>> run h $ ["a" := 1] R.== ["a" := 1]
true

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

Test for inequality 

>>> run h $ 1 R./= False
true

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

Greater than 

>>> run h $ 3 R.> 2
true

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

Greater than or equal to 

>>> run h $ [1] R.>= Null
false

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

Lesser than 

>>> run h $ (str "a") R.< (str "b")
true

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

Lesser than or equal to 

>>> run h $ 2 R.<= 2
true

not :: Expr a => a -> ReQL

Negation 

>>> run h $ R.not False
true
>>> run h $ R.not Null
true

random :: ReQL

A random float between 0 and 1 

>>> run' h $ (\x -> x R.< 1 R.&& x R.>= 0) `apply` [random]
true

randomTo :: ReQL -> ReQL

A random number between 0 and n 

>>> run' h $ (\x -> x R.< 10 R.&& x R.>= 0) `apply` [randomTo 10]
true

randomFromTo :: ReQL -> ReQL -> ReQL

A random number between 0 and n 

>>> run' h $ (\x -> x R.< 10 R.&& x R.>= 5) `apply` [randomFromTo 5 10]
true

Dates and times

now :: ReQL

The time and date when the query is executed 

 >>> run' h $ now

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"
Time<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
Time<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"
Time<2012-01-07 08:34:00 -0700>

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

The same time in a different timezone 

>>> _ <- run' h $ inTimezone "+0800" now

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 R.- (60*60)) (Closed now) $ epochTime 1382919271
false

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

args :: Expr array => array -> ReQL

Splice a list of values into an argument list

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]
8

js :: ReQL -> ReQL

Evaluate a JavaScript expression 

>>> run' h $ js "Math.PI"
3.141592653589793
>>> let r_sin x = js "Math.sin" `apply` [x]
>>> run h $ R.map r_sin [pi, pi/2]
[1.2246063538223773e-16,1]

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

Server-side if 

>>> run h $ branch (1 R.< 2) 3 4
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 "users") (\user -> table "users" # get (user!"name") # ex update [nonAtomic] (const ["post_count" := R.count (table "posts" # R.filter (\post -> post!"author" R.== user!"name"))])) :: IO WriteResponse
{replaced:2}

error :: Expr s => s -> ReQL

Abort the query with an error 

>>> run' h $ R.error (str "haha") R./ 2 + 1
*** Exception: RethinkDB: Runtime error: "haha"
  in add(div({- HERE -} error("haha"), 2), 1)

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

Catch some expections inside the query.

Called default in the official drivers 

>>> run h $ R.handle (const 0) $ ["a" := 1] ! "b"
0
>>> run h $ R.handle (expr . id) $ ["a" := 1] ! "b"
"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

exprList :: [e] -> ReQL

Instances

Expr Bool 
Expr Char 
Expr Double 
Expr Float 
Expr Int 
Expr Int8 
Expr Int16 
Expr Int32 
Expr Int64 
Expr Integer 
Expr Word 
Expr Word8 
Expr Word16 
Expr Word32 
Expr Word64 
Expr () 
Expr ByteString 
Expr ByteString 
Expr ZonedTime 
Expr UTCTime 
Expr Value 
Expr Text 
Expr Text 
Expr Datum 
Expr Table 
Expr Database 
Expr ReQL 
Expr Term 
Expr Unit 
Expr ConflictResolution 
Expr Durability 
Expr PaginationStrategy 
Expr HttpMethod 
Expr HttpResultFormat 
Expr a => Expr [a] 
Expr (Ratio Integer) 
Expr a => Expr (Maybe a) 
Expr a => Expr (Set a) 
Expr a => Expr (Vector a) 
Expr (Attribute a) 
(~ * a ReQL, ~ * b ReQL) => Expr (a -> b -> ReQL) 
~ * a ReQL => Expr (a -> ReQL) 
(Expr a, Expr b) => Expr (Either a b) 
(Expr a, Expr b) => Expr (a, b) 
Expr a => Expr (Map [Char] a) 
Expr a => Expr (Map Text a) 
Expr a => Expr (HashMap [Char] a) 
(Expr k, Expr v) => Expr (HashMap k v) 
Expr a => Expr (HashMap Text a) 
(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
"1"

asArray :: Expr x => x -> ReQL

Convert a value to an array 

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

asString :: Expr x => x -> ReQL

Convert a value to a string 

>>> run h $ asString $ ["a" := 1, "b" := 2]
"{\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")
34

asObject :: Expr x => x -> ReQL

Convert a value to an object 

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

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
"NUMBER"

info :: Expr a => a -> ReQL

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

>>> run h $ info $ table "users"
{"primary_key":"name","name":"users","indexes":["friends","location"],"type":"TABLE","db":{"name":"doctests","type":"DB"}}

json :: ReQL -> ReQL

Parse a json string into an object 

>>> run' h $ json "{\"a\":1}"
{"a":1}

uuid :: ReQL

http :: Expr url => url -> HttpOptions -> ReQL

Retrieve data from the specified URL over HTTP 

>>> _ <- run' h $ http "http://httpbin.org/get" def{ httpParams = Just ["foo" := 1] }
>>> _ <- run' h $ http "http://httpbin.org/put" def{ httpMethod = Just PUT, httpData = Just $ expr ["foo" := "bar"] }

data HttpOptions

Constructors

HttpOptions 

Fields

httpTimeout :: Maybe Int
 
httpReattempts :: Maybe Int
 
httpRedirects :: Maybe Int
 
httpVerify :: Maybe Bool
 
httpResultFormat :: Maybe HttpResultFormat
 
httpMethod :: Maybe HttpMethod
 
httpAuth :: Maybe [Attribute Dynamic]
 
httpParams :: Maybe [Attribute Dynamic]
 
httpHeader :: Maybe [Attribute Dynamic]
 
httpData :: Maybe ReQL
 
httpPage :: Maybe PaginationStrategy
 
httpPageLimit :: Maybe Int
 

Instances

Default HttpOptions 

data HttpResultFormat

Constructors

FormatAuto 
FormatJSON 
FormatJSONP 
FormatBinary 

Instances

data HttpMethod

Constructors

GET 
POST 
PUT 
PATCH 
DELETE 
HEAD 

Instances

data PaginationStrategy

Constructors

LinkNext 
PaginationFunction (ReQL -> ReQL) 

Instances

Geospatial commands

circle :: (Expr point, Expr radius) => point -> radius -> ReQL

Create a polygon approximating a circle 

>>> run' h $ ex circle [numVertices 6, unit Kilometer] (point (-73) 40) 100
Polygon<[[-73,39.099310036015424],[-74.00751390838496,39.54527799206398],[-74.02083610406069,40.445812561599965],[-73,40.900549591978255],[-71.97916389593931,40.445812561599965],[-71.99248609161504,39.54527799206398],[-73,39.099310036015424]]>

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

Distance between a point and another geometry object 

>>> run' h $ distance (point (-73) 40) (point (-122) 37)
4233453.467303547
>>> run' h $ ex distance [unit Mile] (point (-73) 40) (point (-122) 37)
2630.54602825968

fill :: Expr line => line -> ReQL

Convert a line object into a polygon 

>>> run' h $ fill $ line [[-122,37], [-120,39], [-121,38]]
Polygon<[[-122,37],[-120,39],[-121,38],[-122,37]]>

geoJSON :: Expr geojson => geojson -> ReQL

Convert a GeoJSON object into a RethinkDB geometry object 

>>> run' h $ geoJSON ["type" := "Point", "coordinates" := [-45,80]]
Point<[-45,80]>

toGeoJSON :: Expr geo => geo -> ReQL

Convert a RethinkDB geometry object into a GeoJSON object 

>>> run' h $ toGeoJSON $ point (-122.423246) 37.779388
{"coordinates":[-122.423246,37.779388],"type":"Point"}

getIntersecting :: (Expr geo, Expr table) => geo -> Index -> table -> ReQL

Search a geospatial index for intersecting objects 

>>> run' h $ table "places" # getIntersecting (point (-122) 37) (Index "geo")
[]

getNearest :: (Expr point, Expr table) => point -> Index -> table -> ReQL

Query a geospatial index for the nearest matches 

>>> run' h $ table "places" # getNearest (point (-122) 37) (Index "location")
[]
>>> run' h $ table "places" # ex getNearest [maxResults 5, maxDist 10, unit Kilometer] (point (-122) 37) (Index "location")
[]

includes :: (Expr area, Expr geo) => geo -> area -> ReQL

Test whether a geometry object includes another 

>>> run' h $ circle (point (-122) 37) 5000 # includes (point (-120) 48)
false

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

Test if two geometry objects intersects 

>>> run' h $ intersects (line [[-122,37],[-120,48]]) (line [[-120,49],[-122,48]])
false

line :: Expr points => points -> ReQL

Create a line object 

>>> run' h $ line [[-73,45],[-122,37]]
Line<[-73,45],[-122,37]>

point :: (Expr longitude, Expr latitude) => longitude -> latitude -> ReQL

Create a point objects 

>>> run' h $ point (-73) 40
Point<[-73,40]>

polygon :: Expr points => points -> ReQL

Create a polygon object 

>>> run' h $ polygon [[-73,45],[-122,37],[-73,40]]
Polygon<[[-73,45],[-122,37],[-73,40],[-73,45]]>

polygonSub :: (Expr polygon, Expr hole) => hole -> polygon -> ReQL

Punch a hole in a polygon 

>>> run' h $ (polygon [[-73,45],[-122,37],[-73,40]]) # polygonSub (polygon [[-73.2,40.1],[-73.2,40.2],[-73.3,40.1]])
Polygon<[[-73,45],[-122,37],[-73,40],[-73,45]],[[-73.2,40.1],[-73.2,40.2],[-73.3,40.1],[-73.2,40.1]]>

data LonLat

Constructors

LonLat 

Fields

longitude :: Double
 
latitude :: Double
 

Instances

Eq LonLat 
Ord LonLat 
Show LonLat 
ToJSON LonLat 
FromJSON LonLat 

type Line = Vector LonLat

type Polygon = Vector (Vector LonLat)

maxResults :: ReQL -> Attribute a

Optional argument for getNearest

maxDist :: ReQL -> Attribute a

Optional argument for getNearest

unit :: Unit -> Attribute a

Optional argument for getNearest, circle and distance

numVertices :: ReQL -> Attribute a

Optional argument for circle

data Unit

Constructors

Meter 
Kilometer 
Mile 
NauticalMile 
Foot 

Instances

Helpers

ex :: OptArgs a => a -> [Attribute Static] -> a

Extend an operation with optional arguments

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) => a -> (a -> b) -> ReQL

Flipped function application

note :: String -> ReQL -> ReQL

Add a note a a ReQL Term

This note does not get sent to the server. It is used to annotate backtraces and help debugging.

empty :: ReQL

An empty object

def :: Default a => a