用觸發器插入多行：Postgresql

Question

我有一個觸發器：

CREATE OR REPLACE FUNCTION process_fillDerivedFromGenby() RETURNS TRIGGER AS $fillDerivedFromgenby$
  DECLARE
    prog     varchar(255);
    curent   varchar(255);
  BEGIN

    SELECT u.iduseentity ,g.idCreatedEntity into prog,curent
    FROM entity e
    JOIN used u ON e.identity=u.iduseentity
    JOIN activity a ON a.idactivity=u.idusedactivity
    JOIN generatedby g ON g.idcreatoractivity=a.idactivity
    WHERE g.idCreatedEntity =NEW.idCreatedEntity;

    --raise notice 'curent: "%" prog by "%"', curent, prog;

    INSERT INTO DERIVEDFROM VALUES(prog,curent);
    return new;
  END;

$fillDerivedFromgenby$ LANGUAGE plpgsql;
CREATE TRIGGER fillDerivedFromgenby AFTER INSERT ON GENERATEDBY
    FOR EACH ROW EXECUTE PROCEDURE process_fillDerivedFromGenby();

一切正常，但如果我的選擇返回3行，則觸發器將僅插入我的選擇的最后一個值而不是3行。 我已經嘗試過為“ for”創建一個循環，但這是行不通的。

有什么建議么 ？

Answer 1

我已經提供了您其他問題的答案。 具有諷刺意味的是，問題不是重復，而是答案。

這將插入所有行而不通過變量：

CREATE OR REPLACE FUNCTION process_fillDerivedFrom_used() RETURNS TRIGGER AS $fillDerivedFrom_used$
  BEGIN
    INSERT INTO DERIVEDFROM (prog, current)  -- or whatever the column names are
        SELECT u.iduseentity as prog, g.idCreatedEntity as current
        FROM entity e JOIN
             used u
             ON e.identity = u.iduseentity JOIN
             activity a
             ON a.idactivity = u.idusedactivity JOIN
             generatedby g
             ON g.idcreatoractivity = a.idactivity;    
END;

Answer 2

放入“按降序排列”和“限制1”。

SELECT u.iduseentity ,g.idCreatedEntity into prog,curent
FROM entity e
JOIN used u ON e.identity=u.iduseentity
JOIN activity a ON a.idactivity=u.idusedactivity
JOIN generatedby g ON g.idcreatoractivity=a.idactivity
WHERE g.idCreatedEntity =NEW.idCreatedEntity

按u.iduseentity DESC LIMIT 1排序；