demo.txt

customer: 1
first Name: Jon
Middle Name: al
Last Name : David

sha(256,JonalDavid)


Customer 2:
first Name: Jona
Middle Name: l
Last Name : David 

sha(256,JonalDavid);


sha2(256, iifNull(Title,'') +FirstName +iifNull(MiddleName,'') +LastName +iifNull(Suffix,'') +iifNull(CompanyName,'') +iifNull(SalesPerson,'') +iifNull(EmailAddress,'') +iifNull(Phone,''))

--------------------------------------------------------------

create  table person
(

firstName varchar(255),
middleName varchar(255),
LastName varchar(255)
--,phone varchar(255)
);

INSERT INTO person
VALUES ('Jon','al','David','957629886')
INSERT INTO person
VALUES ('Jona','l','David','849515755')


---------------------------------------------------------


declare 
@customer1 varchar(10)= (select '1'),
@firstName1 varchar(50)=  (Select 'Jon'),
@MiddleName1 varchar(50)= (Select 'al'),
@LastName1 varchar(50)= (Select 'David'),

@customer2 varchar(10)= (select '2'),
@firstName2 varchar(50)=  (Select 'Jona'),
@MiddleName2 varchar(50)= (Select 'l'),
@LastName2 varchar(50)= (Select 'David')

select @customer1 Customer_ID, @firstName1 FirstName, @MiddleName1 MiddleName, @LastName1 LastName into dbo.Customer
union 
select @customer2, @firstName2, @MiddleName2, @LastName2 

select * from dbo.Customer c

select c.* , (isnull(firstName,'') +  isnull(middleName,'') +  isnull(LastName,'')) as  concatenatedColumn,
HASHBYTES('SHA2_256',(isnull(firstName,'') +  isnull(middleName,'') +  isnull(LastName,'')) ) as hashKey
from dbo.Customer c