Get birthdate

How to get years old from birthdate. This can also be done with computed columns,

You must execute the code again to save those values in the database.

-- INIT database
CREATE TABLE [dbo].[BirthDays](
	[Id] [INT] IDENTITY(1,1) NOT NULL,
	[FirstName] [NVARCHAR](MAX) NULL,
	[LastName] [NVARCHAR](MAX) NULL,
	[BirthDate] [DATE] NULL,
 CONSTRAINT [PK_BirthDays] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

SET IDENTITY_INSERT BirthDays ON;

INSERT INTO BirthDays ([Id], [FirstName], [LastName], [BirthDate])
VALUES
( 1, N'Stefanie', N'Buckley', N'1967-02-02'),
( 2, N'Sandy', N'Mc Gee', N'1986-06-26'),
( 3, N'Lee', N'Warren', N'1994-07-09'),
( 4, N'Regina', N'Forbes', N'1962-07-12'),
( 5, N'Daniel', N'Kim', N'1979-11-27')

-- QUERY database
SELECT Id,
       FirstName,
       LastName,
       BirthDate
  FROM BirthDays
  
  SELECT Id,
       FirstName,
       LastName,
       BirthDate,
       (CAST(FORMAT(GETDATE(), 'yyyyMMdd') AS INTEGER) - CAST(FORMAT(BirthDate, 'yyyyMMdd') AS INTEGER)) / 10000 AS Age
  FROM BirthDays;

Id	FirstName	LastName	BirthDate
1	Stefanie	Buckley	1967-02-02
2	Sandy	Mc Gee	1986-06-26
3	Lee	Warren	1994-07-09
4	Regina	Forbes	1962-07-12
5	Daniel	Kim	1979-11-27

Id	FirstName	LastName	BirthDate	Age
1	Stefanie	Buckley	1967-02-02	57
2	Sandy	Mc Gee	1986-06-26	38
3	Lee	Warren	1994-07-09	30
4	Regina	Forbes	1962-07-12	62
5	Daniel	Kim	1979-11-27	44

(5 rows affected)

(5 rows affected)

(5 rows affected)