无法删除Postgres触发功能

Question

代码：

DROP function IF EXISTS update_rarity;
CREATE OR REPLACE FUNCTION  update_rarity() RETURNS trigger AS $$
BEGIN
    if  (((select count(raresa) FROM Carta WHERE c.raresa LIKE '%Legendary%')*100  /(select count(raresa) FROM Carta)) <> 17 ) then
        INSERT INTO Warnings(affected_table,error_message,date,user)
        VALUES ('Carta' ,'Proporcions de raresa no respectades: Legendary la proporció actual és '|| (select count(raresa) FROM Carta WHERE raresa LIKE '%Legendary%')  || 'quan hauria de ser 3', CURRENT_DATE, CURRENT_USER);
    end if;
    
    return null;    
END; 
$$ LANGUAGE plpgsql; 

DROP TRIGGER IF EXISTS cards ON Carta;
CREATE OR REPLACE TRIGGER cards
AFTER INSERT OR UPDATE ON  Carta
FOR EACH ROW
EXECUTE FUNCTION update_rarity();

UPDATE carta  SET nom ='Ral Roachs Rascals' ,raresa='Proletari' WHERE nom = 'Rascals';

ERROR:  syntax error in or near of «;»
LINE 1: DROP function IF EXISTS update_rarity;
                                             ^
SQL state: 42601
Character: 38

Answer 1

Postgres 10中介绍了省略Drop功能的功能签名的可能性。在您过时且不受支持的Postgres版本中，您需要包括参数列表（触发功能是空的）：

DROP function IF EXISTS update_rarity();
                                     ^-- this