(1000, N ' ..','19550219','[email protected]',2,1),
(1001, N ' ..','19831203','[email protected]',3,3),
(1002, N ' ..','19760607','[email protected]',1,2),
(1003, N ' ..','19820417','[email protected]',4,3)
, PRIMARY KEY UNIQUE
, PRIMARY KEY UNIQUE (PK_Employees UQ_Employees_Email). CLUSTERED, NONCLUSTERED. , . (CLUSTERED) . CLUSTERED , , , . . , , . , , . , , , NONCLUSTERED:
ALTER TABLE _ ADD CONSTRAINT _
PRIMARY KEY NONCLUSTERED(1,2,)
PK_Employees , UQ_Employees_Email . :
ALTER TABLE Employees DROP CONSTRAINT PK_Employees
ALTER TABLE Employees DROP CONSTRAINT UQ_Employees_Email
CLUSTERED NONCLUSTERED:
ALTER TABLE Employees ADD CONSTRAINT PK_Employees PRIMARY KEY NONCLUSTERED (ID)
ALTER TABLE Employees ADD CONSTRAINT UQ_Employees_Email UNIQUE CLUSTERED (Email)
, Employees, , UQ_Employees_Email:
SELECT * FROM Employees
ID | Name | Birthday | PositionID | DepartmentID | HireDate | |
.. | 1982-04-17 | [email protected] | 2015-04-08 | |||
.. | 1955-02-19 | [email protected] | 2015-04-08 | |||
.. | 1983-12-03 | [email protected] | 2015-04-08 | |||
.. | 1976-06-07 | [email protected] | 2015-04-08 |
, PK_Employees, ID.
, , .. Employees ID - , , .
, , .. , , (, ). , , , , .
|
|
, .
, CLUSTERED NONCLUSTERED .
, , ALTER TABLE _ ADD CONSTRAINT _ :
PRIMARY KEY ;
FOREIGN KEY ;
UNIQUE ;
CHECK ;
DEFAULT ;
, , ALTER TABLE _ DROP CONSTRAINT _.
(CLUSTERED) (NONCLUSTERED) .
, PRIMARY KEY UNIQUE.
:
CREATE INDEX IDX_Employees_Name ON Employees(Name)
CLUSTERED, NONCLUSTERED, UNIQUE, ASC ( ) DESC:
CREATE UNIQUE NONCLUSTERED INDEX UQ_Employees_EmailDesc ON Employees(Email DESC)
NONCLUSTERED , .. , , CLUSTERED NONCLUSTERED .
:
DROP INDEX IDX_Employees_Name ON Employees
, , CREATE TABLE.
:
DROP TABLE Employees
CREATE TABLE:
CREATE TABLE Employees(
ID int NOT NULL,
Name nvarchar (30),
Birthday date,
Email nvarchar (30),
PositionID int,
DepartmentID int,
HireDate date NOT NULL CONSTRAINT DF_Employees_HireDate DEFAULT SYSDATETIME(),
ManagerID int,
CONSTRAINT PK_Employees PRIMARY KEY (ID),
CONSTRAINT FK_Employees_DepartmentID FOREIGN KEY (DepartmentID) REFERENCES Departments(ID),
CONSTRAINT FK_Employees_PositionID FOREIGN KEY (PositionID) REFERENCES Positions(ID),
CONSTRAINT FK_Employees_ManagerID FOREIGN KEY (ManagerID) REFERENCES Employees(ID),
CONSTRAINT UQ_Employees_Email UNIQUE (Email),
CONSTRAINT CK_Employees_ID CHECK (ID BETWEEN 1000 AND 1999),
INDEX IDX_Employees_Name(Name)
)
: