Question

I try to correct this function but is impossible!!
I declare one integer “var_id”, and insert in id_val the value of frist query,
if is null the tag name is inserted in a table and var_id = last insert id, otherwise do the last insert…

CREATE OR REPLACE FUNCTION public."InsertVideoTag"
(
  IN  in_idvideo  integer,
  IN  in_tagname  VARCHAR(25)      
)
RETURNS bigint AS
$$

DECLARE var_id bigint DEFAULT NULL;


SELECT var_id := IDTag FROM Tag WHERE TagName = in_tagname;


IF var_id IS NULL
THEN

INSERT INTO tag (   TagName )
VALUES( in_tagname );

var_id := SELECT CURRVAL(pg_get_serial_sequence('public.tag','idtag'));

END IF;

INSERT INTO video_has_tag 
(                 
  IDVideo,      
  IDTag             
)
VALUES 
(
  in_idvideo,                
  var_id             
);

SELECT CURRVAL(pg_get_serial_sequence('public.video','idvideo'));
$$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER;

Answer 1

CREATE OR REPLACE FUNCTION public."InsertVideoTag"
(
  IN  in_idvideo  integer,
  IN  in_tagname  VARCHAR(25)      
)
RETURNS bigint AS
$$
DECLARE var_id bigint DEFAULT NULL;
begin
var_id := (select IDTag FROM Tag WHERE TagName = in_tagname);
IF var_id IS NULL
THEN
    INSERT INTO tag (   TagName )
    VALUES( in_tagname );
    var_id := (SELECT CURRVAL(pg_get_serial_sequence('public.tag','idtag')));
END IF;
INSERT INTO video_has_tag 
(                 
  IDVideo,      
  IDTag             
)
VALUES 
(
  in_idvideo,                
  var_id             
);
return (SELECT CURRVAL(pg_get_serial_sequence('public.video','idvideo')));
end;
$$
LANGUAGE 'plpgsql'
VOLATILE
CALLED ON NULL INPUT
SECURITY INVOKER;