Which one is the best choice for primary key in SQL Server?
100
e.g.个
CREATE TABLE new_employees
(employeeId UNIQUEIDENTIFIER DEFAULT NEWID(),
fname VARCHAR(20) )
GO
INSERT INTO new_employees(fname) VALUES ('Karin')
GO
100
e.g.个
CREATE TABLE new_employees
(
employeeId int IDENTITY(1,1),
fname varchar (20)
);
INSERT new_employees
(fname)
VALUES
('Karin');
[Material Code](or Business Code,which identity of a material. e.g. customer identifier)
e.g.个
CREATE TABLE new_employees(
[ClientId] [varchar](20) NOT NULL,
[fName] [varchar](20) NULL
)
INSERT new_employees
(ClientID, fname)
VALUES
('C0101000001',--customer identifier，e.g.'C0101000001' a user-defined code.
'Karin');
请给我一些建议，从三个类型标识列中 Select 主键，或者其他 Select .
谢谢!