在Postgresql中用语法错误在“ LANGUAGE”附近创建我的第一个触发器

Question

I need to learn more about postgres but I am trying to write a function that links to a trigger in my postgres db. Normally the functions I write work fine, however, this particular function keeps returning errors around the syntax at the end of my output.

I have a fixtures table with a column called 'Result'. I want to read the scores from the fixture eg Wolves 0:0 Ipswich, and trigger into Result 'Draw'.

The query I am writing is as follows:

CREATE OR REPLACE FUNCTION sppullscoretrigger()
RETURNS trigger

SECURITY DEFINER
AS $BODY$

DECLARE
  payload text;
BEGIN
    SELECT NEW.Home_Side_Score, NEW.Away_Side_Score FROM Fixtures;
        IF    NEW.Home_Side_Score is NULL or NEW.Away_Side_Score is NULL THEN NEW.Result = 'TBC';
        IF NEW.Home_Side_Score = NEW.Away_Side_Score THEN NEW.Result = 'Draw';
        IF NEW.Home_Side_Score > NEW.Away_Side_Score THEN NEW.Result = 'Home_Win';
        IF NEW.Home_Side_Score < NEW.Away_Side_Score THEN NEW.Result = 'Away_Win';
        ELSE NEW.Result = 'Error';
        END IF;


    RETURN NEW;
END
$BODY$
LANGUAGE plpgsql

CREATE TRIGGER trgscore
BEFORE INSERT OR UPDATE
ON Fixtures
FOR EACH ROW
EXECUTE PROCEDURE sppullscoretrigger();

I have only written basic functions before but I am really struggling with getting this trigger to work.

Answer 1

You seem to be using IF when you mean ELSIF . This version compiles;

CREATE OR REPLACE FUNCTION sppullscoretrigger()
RETURNS trigger

SECURITY DEFINER
AS $BODY$

DECLARE
  payload text;
BEGIN
    SELECT NEW.Home_Side_Score, NEW.Away_Side_Score FROM Fixtures;
        IF    NEW.Home_Side_Score is NULL or NEW.Away_Side_Score is NULL THEN NEW.Result = 'TBC';
        ELSIF NEW.Home_Side_Score = NEW.Away_Side_Score THEN NEW.Result = 'Draw';
        ELSIF NEW.Home_Side_Score > NEW.Away_Side_Score THEN NEW.Result = 'Home_Win';
        ELSIF NEW.Home_Side_Score < NEW.Away_Side_Score THEN NEW.Result = 'Away_Win';
        ELSE NEW.Result = 'Error';
        END IF;

    RETURN NEW;
END
$BODY$
LANGUAGE plpgsql

A quick SQLfiddle to test with .