Question

创建一个触发器TR_SIGHTING_DESC，它将自动填充目击描述列根据以下模板。 'BIRD-NAME的鸟类被发现在X-Y部分观察区'

 **CREATE TABLE birds(
bird_id NUMBER,
bird_name VARCHAR2(50)
);

CREATE TABLE sightings(
sighting_id NUMBER,
spotter_id NUMBER,
bird_id NUMBER,
latitude NUMBER,
longitude NUMBER,
sighting_date DATE,
description VARCHAR2(255)
);**

CREATE OR REPLACE TRIGGER "TR_SIGNTING_DESC"
BEFORE INSERT ON sightings
FOR EACH ROW
DECLARE
    X VARCHAR(5)
    Y VARCHAR(7)
    NAME VARCHAR2(50)
BEGIN
    IF (:NEW.latitude >-28.1) THEN
    SET X:='north';
    ELSE
    SET X:='south';
    END IF;
    IF (:NEW.longgitude>151.25) THEN
    SET Y:='eastern';
    ELSE
    SET Y:='western';
    END IF;
    SELECT bird_name INTO NAME FROM birds WHERE bird_id= :NEW.bird_id
    :NEW.description := CONCAT('A bird of the species', NAME, ' was spotted     in the ',X,'-',Y,' part of the observation area')   

END;
/

Answer 1

您应该从触发器文本中删除设置;忘了一些“;”

CREATE OR REPLACE TRIGGER "TR_SIGNTING_DESC"
BEFORE INSERT ON sightings
FOR EACH ROW
DECLARE
    X VARCHAR2(5);
    Y VARCHAR2(7);
    NAME VARCHAR2(50);
BEGIN
    IF (:NEW.latitude >-28.1) THEN
      X :='north';
    ELSE
      X :='south';
    END IF;
    IF (:NEW.longgitude>151.25) THEN
      Y:='eastern';
    ELSE
      Y:='western';
    END IF;
    SELECT bird_name 
      INTO NAME 
      FROM birds 
     WHERE bird_id= :NEW.bird_id;

    :NEW.description := 'A bird of the species' || NAME || ' was spotted     in the ' || X || '-' || Y || ' part of the observation area';

    END;
/

如何使用IF-else语句在oracle中创建触发器，并且输出应该是描述

1 个答案: