Fix #1264, allow bulk RPC call

CHANGELOG.md

@@ -9,6 +9,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 - #690, Add `?columns` query parameter for faster bulk inserts, also ignores unspecified json keys in a payload - @steve-chavez
 - #1239, Add support for resource embedding on materialized views - @vitorbaptista
+- #1264, Add support for bulk RPC call - @steve-chavez
 
 ### Fixed
 

src/PostgREST/QueryBuilder.hs

@@ -148,29 +148,18 @@ callProc :: QualifiedIdentifier -> [PgArg] -> Bool -> SqlQuery -> SqlQuery -> Bo
 callProc qi pgArgs returnsScalar selectQuery countQuery countTotal isSingle paramsAsSingleObject asCsv asBinary binaryField pgVer =
   unicodeStatement sql (HE.param HE.unknown) decodeProc True
   where
-    sql =
-     if returnsScalar then [qc|
-       WITH {argsRecord},
-       {sourceCTEName} AS (
-         SELECT {fromQi qi}({args})
-       )
-       SELECT
-         {countResultF} AS total_result_set,
-         1 AS page_total,
-         {scalarBodyF} AS body,
-         {responseHeaders} AS response_headers
-       FROM ({selectQuery}) _postgrest_t;|]
-     else [qc|
-       WITH {argsRecord},
-       {sourceCTEName} AS (
-         SELECT * FROM {fromQi qi}({args})
-       )
-       SELECT
-         {countResultF} AS total_result_set,
-         pg_catalog.count(_postgrest_t) AS page_total,
-         {bodyF} AS body,
-         {responseHeaders} AS response_headers
-       FROM ({selectQuery}) _postgrest_t;|]
+    sql =[qc|
+      WITH
+      {argsRecord},
+      {sourceCTEName} AS (
+        {sourceBody}
+      )
+      SELECT
+        {countResultF} AS total_result_set,
+        pg_catalog.count(_postgrest_t) AS page_total,
+        {bodyF} AS body,
+        {responseHeaders} AS response_headers
+      FROM ({selectQuery}) _postgrest_t;|]
 
     (argsRecord, args)
       | paramsAsSingleObject = ("_args_record AS (SELECT NULL)", "$1::json")
@@ -182,25 +171,47 @@ callProc qi pgArgs returnsScalar selectQuery countQuery countTotal isSingle para
               "SELECT * FROM json_to_recordset(" <> selectBody <> ") AS _(" <>
                 intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> " " <> pgaType a) <$> pgArgs) <> ")",
             ")"]
-         , intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> " := (SELECT " <> pgFmtIdent (pgaName a) <> " FROM _args_record)") <$> pgArgs))
+         , intercalate ", " ((\a -> pgFmtIdent (pgaName a) <> " := _args_record." <> pgFmtIdent (pgaName a)) <$> pgArgs))
+
+    sourceBody :: SqlFragment
+    sourceBody
+      | paramsAsSingleObject || null pgArgs =
+          if returnsScalar
+            then [qc| SELECT {fromQi qi}({args}) |]
+            else [qc| SELECT * FROM {fromQi qi}({args}) |]
+      | otherwise =
+          if returnsScalar
+            then [qc| SELECT {fromQi qi}({args}) FROM _args_record |]
+            else [qc| SELECT _.*
+                      FROM _args_record,
+                      LATERAL ( SELECT * FROM {fromQi qi}({args}) ) _ |]
+
+    bodyF
+     | returnsScalar = scalarBodyF
+     | isSingle = asJsonSingleF
+     | asCsv = asCsvF
+     | isJust binaryField = asBinaryF $ fromJust binaryField
+     | otherwise = asJsonF
+
+    scalarBodyF
+     | asBinary = asBinaryF _procName
+     | otherwise = unwords [
+        "CASE",
+          "WHEN pg_catalog.count(_postgrest_t) = 1",
+            "THEN (json_agg(_postgrest_t." <> pgFmtIdent _procName <> ")->0)::character varying",
+            "ELSE (json_agg(_postgrest_t." <> pgFmtIdent _procName <> "))::character varying",
+        "END"]
+
     countResultF = if countTotal then "( "<> countQuery <> ")" else "null::bigint" :: Text
     _procName = qiName qi
     responseHeaders =
       if pgVer >= pgVersion96
         then "coalesce(nullif(current_setting('response.headers', true), ''), '[]')" :: Text -- nullif is used because of https://gist.github.com/steve-chavez/8d7033ea5655096903f3b52f8ed09a15
         else "'[]'" :: Text
+
     decodeProc = HD.rowMaybe procRow
     procRow = (,,,) <$> HD.nullableColumn HD.int8 <*> HD.column HD.int8
                     <*> HD.column HD.bytea <*> HD.column HD.bytea
-    scalarBodyF
-     | asBinary = asBinaryF _procName
-     | otherwise = "(row_to_json(_postgrest_t)->" <> pgFmtLit _procName <> ")::character varying"
-
-    bodyF
-     | isSingle = asJsonSingleF
-     | asCsv = asCsvF
-     | isJust binaryField = asBinaryF $ fromJust binaryField
-     | otherwise = asJsonF
 
 pgFmtIdent :: SqlFragment -> SqlFragment
 pgFmtIdent x = "\"" <> replace "\"" "\"\"" (trimNullChars $ toS x) <> "\""

test/Feature/RpcSpec.hs

@@ -349,6 +349,42 @@ spec =
           [json|"Hello, John"|]
           { matchHeaders = [matchContentTypeJson] }
 
+    context "bulk RPC" $ do
+      it "works with a scalar function an returns a json array" $
+        post "/rpc/add_them"
+          [json|[
+            {"a": 1, "b": 2},
+            {"a": 4, "b": 6},
+            {"a": 100, "b": 200}
+          ]|] `shouldRespondWith`
+          [json|
+            [3, 10, 300]
+          |] { matchHeaders = [matchContentTypeJson] }
+
+      it "works with a scalar function an returns a json array when posting CSV" $
+        request methodPost "/rpc/add_them" [("Content-Type", "text/csv")]
+          "a,b\n1,2\n4,6\n100,200"
+          `shouldRespondWith`
+          [json|
+            [3, 10, 300]
+          |]
+          { matchStatus  = 200
+          , matchHeaders = [matchContentTypeJson]
+          }
+
+      it "works with a non-scalar result" $
+        post "/rpc/get_projects_below?select=id,name"
+          [json|[
+            {"id": 1},
+            {"id": 5}
+          ]|] `shouldRespondWith`
+          [json|
+            [{"id":1,"name":"Windows 7"},
+             {"id":2,"name":"Windows 10"},
+             {"id":3,"name":"IOS"},
+             {"id":4,"name":"OSX"}]
+          |] { matchHeaders = [matchContentTypeJson] }
+
     context "only for GET rpc" $ do
       it "should fail on mutating procs" $ do
         get "/rpc/callcounter" `shouldRespondWith` 500

test/fixtures/schema.sql

@@ -1659,4 +1659,9 @@ CREATE TABLE test.openapi_types(
   "a_numeric" numeric,
   "a_real" real,
   "a_double_precision" double precision
-);
+);
+
+create function add_them(a integer, b integer)
+returns integer as $$
+  select a + b;
+$$ language sql;