Question

我有一个基于文章标题查找文章的存储过程。但我还需要在同一个表中增加一个列，该列计算查看文章的次数。

尽量提高效率，我认为有两种方法可以解决这个问题：

执行一次SELECT以获取目标行上的PK。然后使用该PK增加视图的数量，最后使用PK返回另一个SELECT以返回文章数据。
执行一个SELECT将文章数据返回给我的应用程序，然后使用返回的PK再次往返数据库以增加视图数量。

我知道＃1会很快，但它是三次查找。＃2需要两次往返数据库。有没有办法优化这项任务？

编辑根据反馈，我想出了以下内容。感谢您的任何评论或建设性的批评。

DECLARE @Slug VARCHAR(250) -- Stored procedure argument

-- declare @UpdatedArticle table variable 
DECLARE @UpdatedArticle TABLE
(
    ArtID INT,
    ArtUserID UNIQUEIDENTIFIER,
    ArtSubcategoryID INT,
    ArtTitle VARCHAR(250),
    ArtHtml VARCHAR(MAX),
    ArtDescription VARCHAR(350),
    ArtKeywords VARCHAR(250),
    ArtLicenseID VARCHAR(10),
    ArtViews BIGINT,
    ArtCreated DATETIME2(7),
    ArtUpdated DATETIME2(7)
);

UPDATE Article
    SET ArtViews = ArtViews + 1
OUTPUT
    INSERTED.ArtID,
    INSERTED.ArtUserID,
    inserted.ArtSubcategoryID,
    INSERTED.ArtTitle,
    INSERTED.ArtHtml,
    INSERTED.ArtDescription,
    INSERTED.ArtKeywords,
    INSERTED.ArtLicenseID,
    INSERTED.ArtViews,
    INSERTED.ArtUpdated,
    INSERTED.ArtCreated
INTO @UpdatedArticle
WHERE ArtSlugHash = CHECKSUM(@Slug) AND ArtSlug = @Slug AND ArtApproved = 1

SELECT a.ArtID, a.ArtUserID, a.ArtTitle, a.ArtHtml, a.ArtDescription, a.ArtKeywords, a.ArtLicenseID,
    l.licTitle, a.ArtViews, a.ArtCreated, a.ArtUpdated, s.SubID, s.SubTitle, c.CatID, c.CatTitle,
    sec.SecID, sec.SecTitle, u.UsrDisplayName AS UserName
    FROM @UpdatedArticle a
    INNER JOIN Subcategory s ON a.ArtSubcategoryID = s.SubID
    INNER JOIN Category c ON s.SubCatID = c.CatID
    INNER JOIN [Section] sec ON c.CatSectionID = sec.SecID
    INNER JOIN [User] u ON a.ArtUserID = u.UsrID
    INNER JOIN License l ON a.ArtLicenseID = l.LicID

Answer 1

以下是在单个更新语句中使用OUTPUT语句（SQL Server 2005以上版）的方法：

IF OBJECT_ID ('Books', 'U') IS NOT NULL
    DROP TABLE dbo.Books;

CREATE TABLE dbo.Books
(
  BookID int NOT NULL PRIMARY KEY,
  BookTitle nvarchar(50) NOT NULL,
  ModifiedDate datetime NOT NULL,
  NumViews int not null CONSTRAINT DF_Numviews DEFAULT (0)
);

INSERT INTO dbo.Books
  (BookID, BookTitle, ModifiedDate) 
VALUES
  (106, 'abc', GETDATE()),
  (107, 'Great Expectations', GETDATE());


-- declare @UpdateOutput1 table variable 
DECLARE @UpdateOutput1 table
(
  BookID int,
  BookTitle nvarchar(50),
  ModifiedDate datetime,
  NumViews int 
);


-- >>>>  here is the update of Numviews and the Fetch
-- update Numviews in Books table, and retrive the row
UPDATE Books
SET 
  NumViews = NumViews + 1
OUTPUT
    INSERTED.BookID,
    INSERTED.BookTitle,
    INSERTED.ModifiedDate,
    INSERTED.NumViews
  INTO @UpdateOutput1
WHERE BookID = 106

-- view updated row in Books table
SELECT * FROM Books;

-- view output row in @UpdateOutput1 variable
SELECT * FROM @UpdateOutput1;

返回数据和更新行没有多个查找？

1 个答案: