feat: add related orders

src/PostgREST/ApiRequest/QueryParams.hs

@@ -594,10 +594,20 @@ pDelimiter = char '.' <?> "delimiter (.)"
 --
 -- >>> P.parse pOrder "" "json_col->key.asc.nullslast"
 -- Right [OrderTerm {otTerm = ("json_col",[JArrow {jOp = JKey {jVal = "key"}}]), otDirection = Just OrderAsc, otNullOrder = Just OrderNullsLast}]
+--
+-- >>> P.parse pOrder "" "clients(json_col->key).desc.nullsfirst"
+-- Right [OrderRelationTerm {otRelation = "clients", otRelTerm = ("json_col",[JArrow {jOp = JKey {jVal = "key"}}]), otDirection = Just OrderDesc, otNullOrder = Just OrderNullsFirst}]
+--
+-- >>> P.parse pOrder "" "clients(name,id)"
+-- Left (line 1, column 8):
+-- unexpected '('
+-- expecting letter, digit, "-", "->>", "->", delimiter (.), "," or end of input
+--
+-- >>> P.parse pOrder "" "name,clients(name),id"
+-- Right [OrderTerm {otTerm = ("name",[]), otDirection = Nothing, otNullOrder = Nothing},OrderRelationTerm {otRelation = "clients", otRelTerm = ("name",[]), otDirection = Nothing, otNullOrder = Nothing},OrderTerm {otTerm = ("id",[]), otDirection = Nothing, otNullOrder = Nothing}]
 pOrder :: Parser [OrderTerm]
-pOrder = lexeme pOrderTerm `sepBy1` char ','
+pOrder = lexeme (try pOrderRelationTerm <|> pOrderTerm) `sepBy1` char ','
   where
-    pOrderTerm :: Parser OrderTerm
     pOrderTerm = do
       fld <- pField
       dir <- optionMaybe pOrdDir
@@ -605,6 +615,13 @@ pOrder = lexeme pOrderTerm `sepBy1` char ','
              pEnd $> Nothing
       return $ OrderTerm fld dir nls
 
+    pOrderRelationTerm = do
+      nam <- pFieldName
+      fld <- between (char '(') (char ')') pField
+      dir <- optionMaybe pOrdDir
+      nls <- optionMaybe pNulls <* pEnd <|> pEnd $> Nothing
+      return $ OrderRelationTerm nam fld dir nls
+
     pNulls :: Parser OrderNulls
     pNulls = try (pDelimiter *> string "nullsfirst" $> OrderNullsFirst) <|>
              try (pDelimiter *> string "nullslast"  $> OrderNullsLast)

src/PostgREST/ApiRequest/Types.hs

@@ -64,6 +64,7 @@ data ApiRequestError
   | InvalidRpcMethod ByteString
   | LimitNoOrderError
   | NotFound
+  | NotToOne Text Text
   | NoRelBetween Text Text Text
   | NoRpc Text Text [Text] Bool MediaType Bool
   | NotEmbedded Text
@@ -82,12 +83,19 @@ data RangeError
 type NodeName = Text
 type Depth = Integer
 
-data OrderTerm = OrderTerm
-  { otTerm      :: Field
-  , otDirection :: Maybe OrderDirection
-  , otNullOrder :: Maybe OrderNulls
-  }
-  deriving (Eq)
+data OrderTerm
+  = OrderTerm
+    { otTerm      :: Field
+    , otDirection :: Maybe OrderDirection
+    , otNullOrder :: Maybe OrderNulls
+    }
+  | OrderRelationTerm
+    { otRelation  :: FieldName
+    , otRelTerm   :: Field
+    , otDirection :: Maybe OrderDirection
+    , otNullOrder :: Maybe OrderNulls
+    }
+  deriving Eq
 
 data OrderDirection
   = OrderAsc