Refactor rpc to not use count when returning scalar

src/PostgREST/App.hs

@@ -238,8 +238,12 @@ app dbStructure conf apiRequest =
               let p = V.head payload
                   singular = contentType == CTSingularJSON
                   paramsAsSingleObject = iPreferSingleObjectParameter apiRequest
+                  proc = M.lookup (qiName qi) allProcs 
+                  returnsScalar = case proc of
+                    Just ProcDescription{pdReturnType = (Single (Scalar _))} -> True
+                    _ -> False
               row <- H.query () $
-                callProc qi p q cq topLevelRange shouldCount singular
+                callProc qi p returnsScalar q cq topLevelRange shouldCount singular
                          paramsAsSingleObject (contentType == CTTextCSV)
               let (tableTotal, queryTotal, body) =
                     fromMaybe (Just 0, 0, "[]") row
@@ -257,7 +261,7 @@ app dbStructure conf apiRequest =
               uri Nothing = ("http", host, port, "/")
               uri (Just Proxy { proxyScheme = s, proxyHost = h, proxyPort = p, proxyPath = b }) = (s, h, p, b)
               uri' = uri proxy
-              encodeApi ti = encodeOpenAPI (M.elems $ dbProcs dbStructure) ti uri'
+              encodeApi ti = encodeOpenAPI (M.elems allProcs) ti uri'
           body <- encodeApi . toTableInfo <$> H.query schema accessibleTables
           return $ responseLBS status200 [toHeader CTOpenAPI] $ toS body
 
@@ -276,6 +280,7 @@ app dbStructure conf apiRequest =
       filterCol :: Schema -> TableName -> Column -> Bool
       filterCol sc tb Column{colTable=Table{tableSchema=s, tableName=t}} = s==sc && t==tb
       allPrKeys = dbPrimaryKeys dbStructure
+      allProcs = dbProcs dbStructure
       allOrigins = ("Access-Control-Allow-Origin", "*") :: Header
       shouldCount = iPreferCount apiRequest
       schema = toS $ configSchema conf
@@ -287,7 +292,7 @@ app dbStructure conf apiRequest =
             status = rangeStatus lower upper (toInteger <$> tableTotal)
         in (status, contentRange)
 
-      readReq = readRequest (configMaxRows conf) (dbRelations dbStructure) (dbProcs dbStructure) apiRequest
+      readReq = readRequest (configMaxRows conf) (dbRelations dbStructure) allProcs apiRequest
       fldNames = fieldNames <$> readReq
       readDbRequest = DbRead <$> readReq
       mutateDbRequest = DbMutate <$> (mutateRequest apiRequest =<< fldNames)

src/PostgREST/DbStructure.hs

@@ -137,7 +137,9 @@ accessibleProcs =
       qi = QualifiedIdentifier schema name
       pgType = case typ of
         'c' -> Composite qi
-        'p' -> Pseudo name
+        'p' -> if name == "record" -- Only pg pseudo type that is a row type is 'record'
+                 then Composite qi
+                 else Scalar qi
         _   -> Scalar qi -- 'b'ase, 'd'omain, 'e'num, 'r'ange
 
   parseVolatility :: Char -> ProcVolatility

src/PostgREST/QueryBuilder.hs

@@ -144,26 +144,27 @@ createWriteStatement selectQuery mutateQuery wantSingle wantHdrs asCsv rep pKeys
     | otherwise = asJsonF
 
 type ProcResults = (Maybe Int64, Int64, ByteString)
-callProc :: QualifiedIdentifier -> JSON.Object -> SqlQuery -> SqlQuery -> NonnegRange ->
+callProc :: QualifiedIdentifier -> JSON.Object -> Bool -> SqlQuery -> SqlQuery -> NonnegRange ->
   Bool -> Bool -> Bool -> Bool -> H.Query () (Maybe ProcResults)
-callProc qi params selectQuery countQuery _ countTotal isSingle paramsAsJson asCsv =
+callProc qi params returnsScalar selectQuery countQuery _ countTotal isSingle paramsAsJson asCsv =
   unicodeStatement sql HE.unit decodeProc True
   where
-    sql = [qc|
-            WITH {sourceCTEName} AS ({_callSql})
-            SELECT
-              {countResultF} AS total_result_set,
-              pg_catalog.count(_postgrest_t) AS page_total,
-              case
-                when pg_catalog.count(*) > 1 then
-                  {bodyF}
-                else
-                  coalesce(((array_agg(row_to_json(_postgrest_t)))[1]->{_procName})::character varying, {bodyF})
+    sql = 
+     if returnsScalar then [qc|
+       WITH {sourceCTEName} AS ({_callSql})
+       SELECT
+         {countResultF} AS total_result_set,
+         1 AS page_total,
+         (row_to_json(_postgrest_t)->{_procName})::character varying as body
+       FROM ({selectQuery}) _postgrest_t;|]
+     else [qc| 
+       WITH {sourceCTEName} AS ({_callSql})
+       SELECT
+         {countResultF} AS total_result_set,
+         pg_catalog.count(_postgrest_t) AS page_total,
+         {bodyF} as body
+       FROM ({selectQuery}) _postgrest_t;|]
 
-              end as body
-            FROM ({selectQuery}) _postgrest_t;
-          |]
-          -- FROM (select * from {sourceCTEName} {limitF range}) t;
     countResultF = if countTotal then "("<>countQuery<>")" else "null::bigint" :: Text
     _args = if paramsAsJson
                 then insertableValueWithType "json" $ JSON.Object params

src/PostgREST/Types.hs

@@ -38,7 +38,7 @@ data PgArg = PgArg {
 , pgaReq  :: Bool
 } deriving (Show, Eq)
 
-data PgType = Scalar QualifiedIdentifier | Composite QualifiedIdentifier | Pseudo Text deriving (Eq, Show)
+data PgType = Scalar QualifiedIdentifier | Composite QualifiedIdentifier deriving (Eq, Show)
 
 data RetType = Single PgType | SetOf PgType deriving (Eq, Show)