如何在插入记录之前验证员工年龄必须大于 18（创建 table 时使用检查约束很累但不起作用）

Question

--dept table

create table department(
dept_id number(5)  ,
dept_name varchar2(100),
dept_city varchar2(100) ,
dept_country varchar2(100),

CONSTRAINT dept_pk PRIMARY KEY(dept_id)
);
      
insert into department( dept_id, dept_name, dept_city, dept_country )values(1,'hr','hyderabad','india');
insert into department( dept_id, dept_name, dept_city, dept_country )values(2,'marketing','banglore','india');
insert  into department(dept_id,  dept_name, dept_city, dept_country)values(3,'sales','dhaka','bangladesh');


create sequence s1
start with 1
increment by 1;

create table employee(
employee_id number(10)  ,
employee_name varchar2(100) NOT NULL,
employee_age number(3) ,
employee_sal number(9,2),
dept_id    number(5),
CONSTRAINT employee_pk PRIMARY KEY(employee_id),
constraint dept_fk foreign key(dept_id) references department(dept_id)
);

CREATE OR REPLACE TRIGGER trg_before_emp_insr
BEFORE INSERT
  on employee_details
  FOR EACH ROW 
DECLARE
  emp_age number;
BEGIN
  IF (employee_age < 18) THEN
    RAISE_APPLICATION_ERROR(-20000,'Employee age must be greater than or equal to 18.');
  END IF;
END;
/

insert into employee(employee_id, employee_name,  employee_age, employee_sal,dept_id )values(s1.nextval,'ravi',45,7333,1);
insert into employee(employee_id,  employee_name,  employee_age, employee_sal,dept_id  )values(s1.nextval,'sai',74,4451,2);
insert  into employee(employee_id, employee_name,  employee_age, employee_sal,dept_id )values(s1.nextval,'chandu',35,9428,3);
insert  into employee( employee_id,employee_name,  employee_age, employee_sal,dept_id )values(s1.nextval,'raju',7,25422,2);
insert  into employee( employee_id,employee_name,  employee_age, employee_sal,dept_id )values(s1.nextval,'teja',36,7955,1);

select * from employee

Answer 1

您想使用 :NEW 记录从正在插入的行中获取值（并使用 EMPLOYEE table 而不是 EMPLOYEE_DETAILS）：

CREATE OR REPLACE TRIGGER trg_before_emp_insr
BEFORE INSERT
  on employee
  FOR EACH ROW 
BEGIN
  IF (:NEW.employee_age < 18) THEN
    RAISE_APPLICATION_ERROR(-20000,'Employee age must be greater than or equal to 18.');
  END IF;
END;
/

db<>fiddle here

但是，您应该考虑存储出生日期而不是年龄，因为明天（或肯定是明年）年龄值会过时，但存储出生日期和计算年龄不会。

create table employee(
  employee_id   number(10)  ,
  employee_name varchar2(100) NOT NULL,
  employee_dob  DATE,
  employee_sal  number(9,2),
  dept_id       number(5),
  CONSTRAINT employee_pk PRIMARY KEY(employee_id),
  constraint dept_fk foreign key(dept_id) references department(dept_id)
);

CREATE OR REPLACE TRIGGER trg_before_emp_insr
BEFORE INSERT
  on employee
  FOR EACH ROW 
BEGIN
  IF :NEW.employee_dob > TRUNC(ADD_MONTHS(SYSDATE, -18*12)) THEN
    RAISE_APPLICATION_ERROR(-20000,'Employee age must be greater than or equal to 18.');
  END IF;
END;
/

db<>fiddle here

如何在插入记录之前验证员工年龄必须大于 18（创建 table 时使用检查约束很累但不起作用）

how to validate employee age that it must me greater than 18 before inserting record(tiried using check constraint while creating table but not work)

oracle

plsql