Create Trigger to update insert to table specific values only - sql-server

Question

I need to create trigger prevent insert and update to table employee under age 21 and over age 67
what next on the code?
CREATE TRIGGER allowInsertUpdateemployee ON dbo.employee
AFTER UPDATE, INSERT
AS
BEGIN
DECLARE #v_ageLow INT = 21,
#v_ageHigh INT = 67,
#v_dateLow date,
#v_dateHigh date
SET #v_dateLow = DATEADD(YEAR, -1 * #v_ageLow, GETDATE())
SET #v_dateHigh = DATEADD(YEAR, -1 * #v_ageHigh, GETDATE())
END

Answer 1

Since the upper and lower bounds are fixed, a check constraint might be a more appropriate solution than a trigger
ALTER TABLE employee ADD CONSTRAINT ck_employee_age CHECK
(DateOfBirth BETWEEN DATEADD(YEAR,-67,GETDATE()) AND DATEADD(YEAR,-21,GETDATE()))

Answer 2

Use "INSTEAD OF INSERT, UPDATE" trigger;
Use INSERTED table to check new incoming values, raiserror if needed;
Use DELETED table to detect if update is processing (this can
help);
Do manual insert or update then (if needed).
INSERT INTO
dbo.employee
SELECT
*
FROM
INSERTED I

Answer 3

I hope this will do
This will not fetch accurate age , However if your method gets you an accurate date you can use your code with it .
OR
you can also use below code to get age:
SELECT DATEDIFF(Day,'2011-11-03' , GETDATE()) /365
SELECT DATEDIFF(Day,#Age , GETDATE())
/365
CREATE TRIGGER allowInsertUpdateemployee ON dbo.employee
INSTEAD OF Insert
AS
BEGIN
DECLARE #v_ageLow INT,
#v_ageHigh INT,
#v_date date,
--#v_dateHigh date
SET #v_ageLow = SELECT DATEDIFF(Year,#v_date , GETDATE())
SET #v_ageHigh = SELECT DATEDIFF(Year,#v_date , GETDATE())
BEGIN
if(#v_ageLow <21 AND #v_ageHigh >67)
BEGIN
RAISERROR('Cannot Insert or Update where User is not in age limit);
ROLLBACK;
END
ELSE
BEGIN
// else write your insert update query
Insert into values ()
PRINT 'Unable to Insert-- Instead Of Trigger.'
END
END

Answer 4

You have to put OR in the where clause. The employee can't be under 21 AND more than 67.
Create TRIGGER tr_Too_young_or_too_old
ON TableName
AFTER INSERT
AS
if exists ( select *, DATEDIFF(yy, birthdate, GETDATE()) as age
from TableName
where DATEDIFF(yy, birthdate, GETDATE()) < 21 or DATEDIFF(yy, birthdate, GETDATE()) > 67 )
begin
rollback
RAISERROR ('Cannot Insert or Update where User is not in age limit', 16, 1);
end