筆記-Microsoft SQL Server 2008技術內幕：T-SQL語言基礎-08 數據修改

插入數據

T-SQL提供了幾種數據插入的語句：INSERT VALUES、INSERT SELECT、INSERT EXEC、SELECT INTO及BULK INSERT。

INSERT VALUES語句：

INSERT INTO dbo.Orders(orderid, orderdate, empid, custid)
  VALUES(10001, '20090212', 3, 'A');

SQL Server 2008加強了VALUES語句的功能，容許在一條語句中指定由逗號分隔開的多行記錄：

INSERT INTO dbo.Orders
  (orderid, orderdate, empid, custid)
VALUES
  (10003, '20090213', 4, 'B'),
  (10004, '20090214', 1, 'A'),
  (10005, '20090213', 1, 'C'),
  (10006, '20090215', 3, 'C');

 在SQL Server 2008中還能夠用VALUES來構建虛擬表：

SELECT *
FROM ( VALUES
         (10003, '20090213', 4, 'B'),
         (10004, '20090214', 1, 'A'),
         (10005, '20090213', 1, 'C'),
         (10006, '20090215', 3, 'C') )
     AS O(orderid, orderdate, empid, custid);

 INSERT SELECT語句，注意，目標表必須事先存在。

INSERT INTO dbo.Orders(orderid, orderdate, empid, custid)
  SELECT orderid, orderdate, empid, custid
  FROM TSQLFundamentals2008.Sales.Orders
  WHERE shipcountry = 'UK';

 INSERT EXEC語句

INSERT INTO dbo.Orders(orderid, orderdate, empid, custid)
  EXEC TSQLFundamentals2008.Sales.usp_getorders @country = 'France';

 SELECT INTO語句

SELECT orderid, orderdate, empid, custid
INTO dbo.Orders
FROM TSQLFundamentals2008.Sales.Orders;

 SELECT INTO語句會複製來源表的基本結構（包括列名、數據類型、是否容許爲NULL及IDENTITY屬性）和數據。約束、索引及觸發器不會歷來源表中複製過來。

BULK INSERT語句

BULK INSERT dbo.Orders FROM 'c:\temp\orders.txt'
  WITH 
    (
       DATAFILETYPE    = 'char',
       FIELDTERMINATOR = ',',
       ROWTERMINATOR   = '\n'
    );

帶有TOP選項的數據更新

如下代碼將刪除具備最小訂單ID值的50個訂單，而不是隨機刪除50行：

WITH C AS
(
  SELECT TOP(50) *
  FROM dbo.Orders
  ORDER BY orderid
)
DELETE FROM C;

OUTPUT子句

INSERT INTO dbo.T1(datacol)
  OUTPUT inserted.keycol, inserted.datacol
    SELECT lastname
    FROM TSQLFundamentals2008.HR.Employees
    WHERE country = N'USA';

 OUTPUT子句爲每一個修改過的行返回一個輸出行。若是有一個需求，出於審覈的目的，須要把修改過的行的一個子集導入一個表：

INSERT INTO dbo.ProductsAudit(productid, colname, oldval, newval)
  SELECT productid, N'unitprice', oldval, newval
  FROM (UPDATE dbo.Products
          SET unitprice *= 1.15
        OUTPUT 
          inserted.productid,
          deleted.unitprice AS oldval,
          inserted.unitprice AS newval
        WHERE SupplierID = 1) AS D
  WHERE oldval < 20.0 AND newval >= 20.0;