SQL Server/T-SQL Tutorial/Query/AS — различия между версиями

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м (1 версия)
 
(нет различий)

Версия 13:46, 26 мая 2010

An alias allows you to change the name of a column in the result set

4>
5> CREATE TABLE OrderDetails (
6>      OrderID int NOT NULL ,
7>      ProductID int NOT NULL ,
8>      UnitPrice money NOT NULL DEFAULT (0),
9>      Quantity smallint NOT NULL DEFAULT (1),
10>     Discount real NOT NULL DEFAULT (0)
11> )
12> GO
1> INSERT OrderDetails VALUES(10248,11,14,12,0)
2> INSERT OrderDetails VALUES(10248,42,9.8,10,0)
3> INSERT OrderDetails VALUES(10248,72,34.8,5,0)
4> INSERT OrderDetails VALUES(10249,14,18.6,9,0)
5> INSERT OrderDetails VALUES(10249,51,42.4,40,0)
6> INSERT OrderDetails VALUES(10250,41,7.7,10,0)
7> INSERT OrderDetails VALUES(10250,51,42.4,35,0.15)
8> INSERT OrderDetails VALUES(10250,65,16.8,15,0.15)
9> INSERT OrderDetails VALUES(10251,22,16.8,6,0.05)
10> INSERT OrderDetails VALUES(10251,57,15.6,15,0.05)
11> go
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>
2>    SELECT OrderID, MIN(Quantity) AS Minimum, MAX(Quantity) AS Maximum
3>    FROM OrderDetails
4>    WHERE OrderID BETWEEN 11000 AND 11002
5>    GROUP BY OrderID
6> GO
OrderID     Minimum Maximum
----------- ------- -------
(0 rows affected)
1>
2> drop table OrderDetails;
3> GO


Use the AS keyword in some places to add column alias

4>
5>
6> CREATE TABLE OrderDetails (
7>      OrderID int NOT NULL ,
8>      ProductID int NOT NULL ,
9>      UnitPrice money NOT NULL DEFAULT (0),
10>     Quantity smallint NOT NULL DEFAULT (1),
11>     Discount real NOT NULL DEFAULT (0)
12> )
13> GO
1> INSERT OrderDetails VALUES(10248,11,14,12,0)
2> INSERT OrderDetails VALUES(10248,42,9.8,10,0)
3> INSERT OrderDetails VALUES(10248,72,34.8,5,0)
4> INSERT OrderDetails VALUES(10249,14,18.6,9,0)
5> INSERT OrderDetails VALUES(10249,51,42.4,40,0)
6> INSERT OrderDetails VALUES(10250,41,7.7,10,0)
7> INSERT OrderDetails VALUES(10250,51,42.4,35,0.15)
8> INSERT OrderDetails VALUES(10250,65,16.8,15,0.15)
9> INSERT OrderDetails VALUES(10251,22,16.8,6,0.05)
10> INSERT OrderDetails VALUES(10251,57,15.6,15,0.05)
11> go
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>
2>    SELECT OrderID AS "Order Number", MIN(Quantity) Minimum, MAX(Quantity) Maximum
3>    FROM OrderDetails
4>    WHERE OrderID BETWEEN 11000 AND 11002
5>    GROUP BY OrderID
6> GO
Order Number Minimum Maximum
------------ ------- -------
(0 rows affected)
1>
2> drop table OrderDetails;
3> GO