postgres json parameter to a function

Question

CREATE OR REPLACE FUNCTION public.writecalculations(id integer, times integer, j json)
  RETURNS text
  LANGUAGE plv8
AS
$body$
var overallStart = new Date();
  var result = 0;
  var insertStmt = "Insert into \"CalculationResult\" Values($1,$2,$3::json)"
  result += plv8.execute(insertStmt,[id, times, j]);     

  var loopEnd = new Date();
  return JSON.stringify({"AffectedRows": result,  "OverallRuntime": loopEnd-overallStart}) ;
$body$
 IMMUTABLE STRICT
 COST 100;


COMMIT;

This gives an error when executed using

WbCall calculationResult(4,4,'{\"a\":1}');

Error :

An error occurred when executing the SQL command: ERROR: function calculationresult(integer, integer, unknown) does not exist Hint: No function matches the given name and argument types. You might need >to add explicit type casts. Position: 15 [SQL State=42883]

What am I doing wrong? I tried various options of passing text with "" and '' and also as passing json

Solution

try:

WbCall calculationResult(4,4,'{"a":1}'::json);

calculationresult(integer, integer, unknown) - PostgreSQL didn't detect type of '{"a":1}', so it ask you to add explicit type casts.