--1.创建数据库主密钥
use master key
go
Create master key
encrypyion by password = 'Password'
go
--2.创建存放加密数据的表
Create table dbo.secTable
(ID int identity primary key,
 [data] nvarchar(100))
go
--3.创建数字证书,数字证书的密钥被数据库主密钥加密
Create certificate Tomcert
with
    subject = 'Tom Certificate',
expiry_date = '2007-01-01'

--4.创建对称密钥,被用证书对其进行加密
create symmetric key sym_tom
with algorithm = desx encryption by certificate TomCrrt
--5.使用证书解开对称密钥,将数据使用对称密钥加密后存储于表中,完成后关闭对称密钥
open symmetric key sym_Tom decryption by certicate tomcert

insert into sectable (data) values(encryptbykey(key_guid('sym_Tom'),N'TOM1'))
insert into sectable (data) values(encryptbykey(key_guid('sym_Tom'),N'TOM2'))
insert into sectable (data) values(encryptbykey(key_guid('sym_Tom'),N'TOM3'))

close symmetric key sym_Tom

--6.查看被加密的数据内容
select * from dbo.SecTable

--7.使用证书解开对称密钥,解密数据表中的数据,完成后关闭对称密钥

select ID,Cast(DecryptByKey(Data) as NVarchar) from dbo.secTable

Close SymmetRic key Sym_Tom