创建和SQL Server

Question

执行功能我有四个表：

1. dbo.Projects
2. dbo.Locations（ID，地点名称）
3. dbo.Purpose（ID，Purposename）
4. dbo.Types（ID，typname）

我有一个搜索条件，这个条件是填充数据库表中的数据：locations,purpose和types。

我想创建一个函数，该函数根据其他表从projects的搜索结果返回表。我创建了一个，但它并没有做我所需要的：

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，所以不胜感激。

Answer 1

我会去：

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 

，如果你只想返回项目其中全部满足的条件并且输入参数中的空字符串被视为通配符：

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' 

当将输入参数值与表中的字段值进行比较时，这还会删除任何区分大小写。我仍然会使用LEFT JOIN而不是INNER JOIN，以防万一某些项目记录可能存在错误的LocationID，PurposeID或TypeID值。

如果你想回到那里从输入参数标准的任何满足（当至少一个输入参数包含的值不把空的输入参数作为通配符）项目，你可以改变AND S IN在WHERE子句OR S和传递NULL任何输入参数，你不希望为其指定值：

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荷兰国际集团不需要输入参数是必要的，因为在这里调用函数中的任何一个空字符串输入参数将导致全部重新正在退回的电源线：

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

Answer 2

这些连接看起来不合适我。你没有完全指定你的模式，所以我猜测，但有一个使用这些连接的情况是非常不寻常的。

在这个示例中，我更改了为每个连接指定的列，但我猜测列中的列可能会被命名。

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，如果我错过了问题或显示注释东西，这不是答案...