Files
postgrest/src/PostgREST/Query.hs
T

59 lines
3.1 KiB
Haskell

{-# LANGUAGE RecordWildCards #-}
{-|
Module : PostgREST.Query
Description : PostgREST query building
TODO: This module shouldn't depend on SchemaCache: once OpenAPI is removed, this can be done
-}
module PostgREST.Query
( mainQuery
, MainQuery (..)
) where
import qualified Hasql.DynamicStatements.Snippet as SQL hiding (sql)
import qualified PostgREST.Query.PreQuery as PreQuery
import qualified PostgREST.Query.QueryBuilder as QueryBuilder
import qualified PostgREST.Query.SqlFragment as SqlFragment
import qualified PostgREST.Query.Statements as Statements
import PostgREST.ApiRequest (ApiRequest (..))
import PostgREST.ApiRequest.Preferences (Preferences (..),
shouldExplainCount)
import PostgREST.Auth.Types (AuthResult (..))
import PostgREST.Config (AppConfig (..))
import PostgREST.Plan (ActionPlan (..),
CrudPlan (..),
DbActionPlan (..),
InspectPlan (..))
import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..))
import Protolude hiding (Handler)
-- The Queries that run on every request
data MainQuery = MainQuery
{ mqTxVars :: SQL.Snippet -- ^ the transaction variables that always run on each query
, mqPreReq :: Maybe SQL.Snippet -- ^ the pre-request function that runs if enabled
-- TODO only one of the following queries actually runs on each request, once OpenAPI is removed from core it will be easier to refactor this
, mqMain :: SQL.Snippet
, mqOpenAPI :: (SQL.Snippet, SQL.Snippet, SQL.Snippet)
, mqExplain :: Maybe SQL.Snippet -- ^ the explain query that gets generated for the "Prefer: count=estimated" case
}
mainQuery :: ActionPlan -> AppConfig -> ApiRequest -> AuthResult -> Maybe QualifiedIdentifier -> MainQuery
mainQuery (NoDb _) _ _ _ _ = MainQuery mempty Nothing mempty (mempty, mempty, mempty) mempty
mainQuery (Db plan) conf@AppConfig{..} apiReq@ApiRequest{iTopLevelRange=range, iPreferences=Preferences{..}} authRes preReq =
let genQ = MainQuery (PreQuery.txVarQuery plan conf authRes apiReq) (PreQuery.preReqQuery <$> preReq) in
case plan of
DbCrud _ WrappedReadPlan{..} ->
let countQuery = QueryBuilder.readPlanToCountQuery wrReadPlan in
genQ (Statements.mainRead wrReadPlan countQuery preferCount configDbMaxRows range pMedia wrHandler) (mempty, mempty, mempty)
(if shouldExplainCount preferCount then Just (Statements.postExplain countQuery) else Nothing)
DbCrud _ MutateReadPlan{..} ->
genQ (Statements.mainWrite mrReadPlan mrMutatePlan pMedia mrHandler preferRepresentation preferResolution) (mempty, mempty, mempty) mempty
DbCrud _ CallReadPlan{..} ->
genQ (Statements.mainCall crProc crCallPlan crReadPlan preferCount configDbMaxRows range pMedia crHandler) (mempty, mempty, mempty) mempty
MayUseDb InspectPlan{ipSchema=tSchema} ->
genQ mempty (SqlFragment.accessibleTables tSchema, SqlFragment.accessibleFuncs tSchema, SqlFragment.schemaDescription tSchema) mempty