創建和SQL Server

Question

執行功能我有四個表：

1. dbo.Projects
2. dbo.Locations（ID，地點名稱）
3. dbo.Purpose（ID，Purposename）
4. dbo.Types（ID，typname）

我有一個搜索條件，這個條件是填充數據庫表中的數據：locations,purpose和types。

我想創建一個函數，該函數根據其他表從projects的搜索結果返回表。我創建了一個，但它並沒有做我所需要的：

ALTER FUNCTION SearchProjects 
(
    @location nvarchar(50), 
    @purpose nvarchar(50), 
    @type nvarchar(50) 
) 
RETURNS TABLE 
AS 
RETURN 
(
     SELECT dbo.Projects.ProjectName, dbo.Projects.Areas,   
      dbo.Projects.PaymentSystem, dbo.Projects.ReceivedDate,  
      dbo.Projects.PropertyClassification, 
      dbo.Projects.ProjectImage 
     FROM dbo.Locations INNER JOIN 
     INNER JOIN dbo.Projects ON dbo.Locations.ID = dbo.Projects.ID  
     INNER JOIN dbo.Purpose ON dbo.Locations.ID = dbo.Purpose.ID 
     INNER JOIN dbo.Types ON dbo.Locations.ID = dbo.Types.ID 
     WHERE (Projects.ProjectName like N'%'+ @location +'%' 
     and Purpose.PurposeName = N'%'+ @purpose +'%' 
     and Types.TypeName like N'%'+ @type  +'%') 
) 
GO 
SELECT * FROM dbo.SearchProjects('',' ',''); 

我是SQL SERVER的新手，所以不勝感激。

Answer 1

我會去：

ALTER FUNCTION SearchProjects (
    @location NVARCHAR(50), 
    @purpose NVARCHAR(50), 
    @type NVARCHAR(50)) 
RETURNS TABLE 
AS 
RETURN 
(
    SELECT p.ProjectName, 
      p.Areas, 
      p.PaymentSystem, 
      p.ReceivedDate,  
      p.PropertyClassification, 
      p.ProjectImage, 
      l.LocationName, 
      pur.PurposeName, 
      t.TypeName 
    FROM dbo.Projects AS p 
    LEFT JOIN dbo.Locations AS l ON p.LocationID = l.ID  
    LEFT JOIN dbo.Purposes pur ON p.PurposeID = pur.ID 
    LEFT JOIN dbo.[Types] AS t ON p.TypeID = t.ID 
    WHERE UPPER(ISNULL(l.LocationName,N'')) LIKE N'%' + UPPER(@location) + '%' 
    AND UPPER(ISNULL(pur.PurposeName,N'')) LIKE N'%' + UPPER(@purpose) + '%' 
    AND UPPER(ISNULL(t.TypeName,N'')) LIKE N'%' + UPPER(@type) + '%' 
    ) 
GO 

，如果你只想返回項目其中全部滿足的條件並且輸入參數中的空字符串被視爲通配符：

SELECT * FROM dbo.SearchProjects('','',''); -- Returns all records 

SELECT * FROM dbo.SearchProjects('north','',''); -- Returns all records with LocationName containing 'north' 
SELECT * FROM dbo.SearchProjects('','research',''); -- Returns all records with PurposeName containing 'research' 
SELECT * FROM dbo.SearchProjects('','','closed'); -- Returns all records with TypeName containing 'closed' 

SELECT * FROM dbo.SearchProjects('north','research',''); -- Returns all records with LocationName containing 'north' and PurposeName containing 'research' 

當將輸入參數值與表中的字段值進行比較時，這還會刪除任何區分大小寫。我仍然會使用LEFT JOIN而不是INNER JOIN，以防萬一某些項目記錄可能存在錯誤的LocationID，PurposeID或TypeID值。

如果你想回到那裏從輸入參數標準的任何滿足（當至少一個輸入參數包含的值不把空的輸入參數作爲通配符）項目，你可以改變AND S IN在WHERE子句OR S和傳遞NULL任何輸入參數，你不希望爲其指定值：

ALTER FUNCTION SearchProjects (
    @location NVARCHAR(50), 
    @purpose NVARCHAR(50), 
    @type NVARCHAR(50)) 
RETURNS TABLE 
AS 
RETURN 
(
    SELECT p.ProjectName, 
      p.Areas, 
      p.PaymentSystem, 
      p.ReceivedDate,  
      p.PropertyClassification, 
      p.ProjectImage, 
      l.LocationName, 
      pur.PurposeName, 
      t.TypeName 
    FROM dbo.Projects AS p 
    LEFT JOIN dbo.Locations AS l ON p.LocationID = l.ID  
    LEFT JOIN dbo.Purposes pur ON p.PurposeID = pur.ID 
    LEFT JOIN dbo.[Types] AS t ON p.TypeID = t.ID 
    WHERE UPPER(ISNULL(l.LocationName,N'')) LIKE N'%' + UPPER(@location) + '%' 
    OR UPPER(ISNULL(pur.PurposeName,N'')) LIKE N'%' + UPPER(@purpose) + '%' 
    OR UPPER(ISNULL(t.TypeName,N'')) LIKE N'%' + UPPER(@type) + '%' 
    ) 
GO 


SELECT * FROM dbo.SearchProjects('','',''); -- Returns all records 

SELECT * FROM dbo.SearchProjects('north',NULL,NULL); -- Returns all records with LocationName containing 'north' 
SELECT * FROM dbo.SearchProjects(NULL,'research',NULL); -- Returns all records with PurposeName containing 'research' 
SELECT * FROM dbo.SearchProjects(NULL,NULL,'closed'); -- Returns all records with TypeName containing 'closed' 

SELECT * FROM dbo.SearchProjects('north','research',NULL); -- Returns all records with LocationName containing 'north' or PurposeName containing 'research' 

NULL荷蘭國際集團不需要輸入參數是必要的，因爲在這裏調用函數中的任何一個空字符串輸入參數將導致全部重新正在退回的電源線：

SELECT * FROM dbo.SearchProjects('north','',''); 
SELECT * FROM dbo.SearchProjects('north','research',''); 
SELECT * FROM dbo.SearchProjects('north','','closed'); 

Answer 2

這些連接看起來不合適我。你沒有完全指定你的模式，所以我猜測，但有一個使用這些連接的情況是非常不尋常的。

在這個示例中，我更改了爲每個連接指定的列，但我猜測列中的列可能會被命名。

Alter FUNCTION SearchProjects (
    @location nvarchar(50), 
    @purpose nvarchar(50), 
    @type nvarchar(50)) 
RETURNS TABLE 
AS 
RETURN 
(
SELECT p.ProjectName, 
    p.Areas, 
    p.PaymentSystem, 
    p.ReceivedDate,  
    p.PropertyClassification, 
    p.ProjectImage 
    FROM dbo.Projects As p 
    LEFT JOIN dbo.Locations As l ON p.LocationID = l.ID  
    LEFT JOIN dbo.Purpose ON p.PurposeID = Purpose.ID 
    LEFT JOIN dbo.Types As t ON p.TypeID = t.ID 
    WHERE (l.LocationName like N'%'+ @location +'%' 
     OR Purpose.PurposeName = N'%'+ @purpose +'%' 
     OR t.TypeName like N'%'+ @type  +'%') 
) 
GO 

SELECT * FROM dbo.SearchProjects('',' ',''); 

很抱歉，如果我錯過了問題或顯示註釋東西，這不是答案...