Question

我正在尝试创建一个触发器，当我：

INSERT INTO sightings (spotter_id, bird_id, latitude,
longitude, sighting_date)
    VALUES (2457, 901, -28.0, 152, '09-MAR-2016');

目击表中的描述将包含：

'在（X），（Y）部分发现了一种鸟类（BIRD-NAME）观察区域

这就是我目前的情况：

CREATE OR REPLACE TRIGGER TR_SIGHTING_DESC
BEFORE INSERT ON sightings
 REFERENCING NEW ROW AS New
FOR EACH ROW
    SET New.description = CONCAT(CONCAT(CONCAT(‘A bird of the species ' bird_name ' was spotted in the ' latitude,
longitude ' part of the
observation area’
)));
END;
/

使用触发器的新手。我是在正确的轨道上吗？

Answer 1

您要插入的值可使用：new pseudorecord。所以你的触发器将是：

CREATE OR REPLACE TRIGGER TR_SIGHTING_DESC
BEFORE INSERT ON sightings
FOR EACH ROW
BEGIN    
    :new.description := 'A bird of the species ' 
                        || :new.bird_name 
                        || ' was spotted in the ' 
                        || :new.latitude || ','|| :new.longitude 
                        || ' part of the observation area';
END;

请参阅本文档中有关关联名称和伪记录的部分。 https://docs.oracle.com/cd/E18283_01/appdev.112/e17126/triggers.htm

Answer 2

这有用吗？

CREATE OR REPLACE TRIGGER TR_SIGHTING_DESC
BEFORE INSERT ON sightings
FOR EACH ROW
BEGIN    
    SELECT 'A bird of the species ' || bird_name || ' was spotted in the ' || latitude || longitude || ' part of the observation area'
    INTO :new.description
    FROM dual;
END;

oracle sql触发尝试创建自动填充描述

2 个答案: