如何寫多條件觸發在MySQL

Question

我做了兩個表具有以下字段：

TABLE 1: "demo" 
FIELD: "demoid" 
FIELD: "cpid" 
FIELD: "status"  


TABLE 2: "sample" 
FIELD: "id" 
FIELD: "conid"  
FIELD: "statussample" 
FIELD: "date" 

我想只要樣本表字段statussample得到改變更新status。 條件是

1) `demoid` and `id` would be same and `cpid` and `conid` would be same.(if more than one values comes i want the last inserted value of `sample` using the field `date`) 

那怎麼辦？我已經堅持了this..new來觸發格式

Answer 1

DELIMITER // 

CREATE TRIGGER sample_after_update 
AFTER UPDATE 
    ON sample FOR EACH ROW 

BEGIN 

    UPDATE demo 
    SET demoid = NEW.id, 
     cpid = NEW.conid 

END; // 
DELIMITER;