Sqlite教程

SQLite After Delete

它指定在删除数据后如何创建触发器。我们有两个表COMPANY和AUDIT。
COMPANY表:
CREATE TABLE COMPANY(
   ID int PRIMARY KEY     NOT null,
   NAME           TEXT    NOT null,
   AGE            int     NOT null,
   ADDRESS        CHAR(50),
   SALARY         REAL
);
审核表:
CREATE TABLE AUDIT(
    EMP_ID int NOT null,
    ENTRY_DATE TEXT NOT null
); 
删除后创建触发器:
使用以下语法在删除操作后在COMPANY表上创建名为" after_del"的触发器。
CREATE TRIGGER after_del  AFTER DELETE  
ON COMPANY
BEGIN
INSERT INTO AUDIT(EMP_ID, ENTRY_DATE) VALUES (new.ID, datetime('now'));
END;
删除后的Sqlite触发器1
现在从旧表中删除记录:
DELETE FROM COMPANY;
删除后的Sqlite触发器2
请参见触发器:
SELECT name FROM sqlite_master
WHERE type = 'trigger'; 
输出:
删除后的SQLite触发器3
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