Postgresql function invocation - postgresql

Question

I've written a postgresql function shown as follows
CREATE OR REPLACE FUNCTION public."UpdateTx"(IN "instructionId" character varying,IN txdata character varying,IN txdetail character varying,IN txstatus character varying,IN resid character varying,IN "timestamp" bigint)
RETURNS character varying
LANGUAGE 'plpgsql'
VOLATILE
PARALLEL UNSAFE
COST 100
AS $BODY$DECLARE updateClause varchar;
BEGIN
IF instructionId = '' THEN
RAISE EXCEPTION 'instruction id is missing';
END IF;
IF txstatus = '' THEN
RAISE EXCEPTION 'tx status is missing';
END IF;
updateClause := CONCAT('txstatus= ', txstatus);
IF txData != '' THEN
updateClause = CONCAT(updateClause, ', ', 'txdata=', txdata);
END IF;
EXECUTE 'UPDATE transactions SET $1 WHERE instructionid=instructionid' USING updateClause;
END;
$BODY$;
So it expects 5 varchar & 1 bigint as input arguments.
I've tried to execute the following SQL query
Select UpdateTx('123'::varchar, 'test'::varchar, 'test'::varchar, 'test'::varchar, 'test2'::varchar, 4124::bigint)
but it keeps showing this error message
ERROR: function updatetx(character varying, character varying, character varying, character varying, character varying, bigint) does not exist
LINE 1: Select UpdateTx('123'::varchar, 'test'::varchar, 'test'::var...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
SQL state: 42883
Character: 8
Is the syntax incorrect?
Appreciate any suggestions or answers :)

Answer 1

Your immediate problem is that your function is declared as case-sensitive (with surrounding double quotes), but you call it in a case-insensitive manner (without the quotes, which, to Postgres, is equivalent to all lower caps). The names just do not match.
But there is more to it:
the way you pass variables is not OK; instead of concatenating part of the query into variable updateClause, you should pass a parameter for each value that needs to be passed to the variable - but better yet, you don't actually need dynamic SQL for this
Don't use variables that conflict with column names
I suspect that you want nulls instead of empty string (it makes much more sense to indicate the "lack" of a value)
the function needs to return something
I also notice that you are not using all arguments that are passed to function
Here is a function code, that, at least, compiles. You can start from there and adapt it to your exact requirement:
CREATE OR REPLACE FUNCTION public.UpdateTx(
IN pInstructionId character varying,
IN pTxdata character varying,
IN pTxdetail character varying, -- not used in the function
IN pTxstatus character varying,
IN pResid character varying, -- not used in the function
IN pTimestamp bigint - - not used in the function
)
RETURNS character varying
LANGUAGE plpgsql
VOLATILE
PARALLEL UNSAFE
COST 100
AS $BODY$
BEGIN
IF pInstructionId IS NULL THEN
RAISE EXCEPTION 'instruction id is missing';
END IF;
IF pTxstatus IS NULL THEN
RAISE EXCEPTION 'tx status is missing';
END IF;
UPDATE transactions
SET txstatus = pTxstatus, txData = COALESCE(pTxdata, txData)
WHERE instructionid = pInstructionId;
RETURN 1; -- put something more meaningful here
END;
$BODY$;
You would invoke it as follows:
select UpdateTx(
'123'::varchar,
'test'::varchar,
'test'::varchar,
'test'::varchar,
'test2'::varchar,
4124::bigint
)
Demo on DB Fiddle