Question

我正在创建一个使用STUFF函数的视图。我想将STUFF的结果放在一个变量中供我查看。我遇到的问题是声明我的变量。它在“DECLARE＆＃39;附近”给我提供了消息＆＃34;不正确的语法。期待＆＃39;（＆＃39;或SELECT。＆＃34; 我已经拥有了＆＃39;（＆＃39;在那里。我已经尝试过将BEGIN放在它之前。我试过把它放在SELECT之后。但似乎什么都没有用，我在搜索中找不到解决方案。我使用的是SQL Server 2012

CREATE VIEW [AQB_OB].[GISREQUESTEDBURNS] 
AS

(DECLARE @CONDITIONS AS varchar(20)
SET @CONDITIONS = (SELECT DISTINCT BD.[RequestedBurnsID]
,[ConditionsReasonsID] = STUFF((SELECT ', ' + CONVERT(VARCHAR (20),[ConditionsReasonsID]) FROM [AQB_OB].[BurnDecisions] WHERE [RequestedBurnsID]= BD.[RequestedBurnsID] ORDER BY [RequestedBurnsID] ASC
FOR XML PATH ('')) , 1 , 1, '') FROM
[AQB_OB].[BurnDecisions] BD)

SELECT RB.[RequestedBurnsID] AS REQUESTEDBURNID
  ,BUY.[BurnYear] AS BURNYEAR
  ,CY.[CurrentYear] AS CURRENTYEAR
  ,RB.[BurnSitesID] AS BURNSITESID
  ,[BurnerID] AS BURNERID
  ,[Contact] AS CONTACT
  ,[BurnDecision] AS BURNDECISION
  ,RB.[Comment] AS COMMENT
  ,@CONDITIONS AS CONDITIONS
FROM [AQB_MON].[AQB_OB].[RequestedBurns] RB
LEFT join AQB_MON.[AQB_OB].[PileDryness] PD on RB.[PileDrynessID] = PD.[PileDrynessID]
inner join AQB_MON.[AQB_OB].[BurnYear] BUY on BUY.BurnYearID = BP.BurnYearID
inner join AQB_MON.[AQB_OB].[CurrentYear] CY on CY.CurrentYearID = BUY.CurrentYearID

GO

Answer 1

您无法在视图中声明变量。你能把它变成函数或存储过程吗？

编辑 - 您也可以将某些东西放入CTE并将其保存为视图。

e.g。

with conditions as 
(
 ... do the STUFF here
)
select blah
from blah
inner join conditions
(or cross join conditions if its just one row, I can't quite decipher what your data is like)

Answer 2

尝试将条件子查询直接放在view select语句中。您可以将XML转换为VARCHAR（20）。

CREATE VIEW [AQB_OB].[GISREQUESTEDBURNS] 
AS    
SELECT RB.[RequestedBurnsID] AS REQUESTEDBURNID
  ,BUY.[BurnYear] AS BURNYEAR
  ,CY.[CurrentYear] AS CURRENTYEAR
  ,RB.[BurnSitesID] AS BURNSITESID
  ,[BurnerID] AS BURNERID
  ,[Contact] AS CONTACT
  ,[BurnDecision] AS BURNDECISION
  ,RB.[Comment] AS COMMENT,

 (
     SELECT DISTINCT BD.[RequestedBurnsID],
             [ConditionsReasonsID] = STUFF((SELECT ', ' + CONVERT(VARCHAR (20),     [ConditionsReasonsID]) FROM [AQB_OB].[BurnDecisions] 
     WHERE [RequestedBurnsID]= BD.[RequestedBurnsID] ORDER BY [RequestedBurnsID] ASC
    FOR XML PATH ('')) , 1 , 1, '') FROM
    [AQB_OB].[BurnDecisions] BD
 ) AS CONDITIONS

FROM [AQB_MON].[AQB_OB].[RequestedBurns] RB
LEFT join AQB_MON.[AQB_OB].[PileDryness] PD on RB.[PileDrynessID] = PD.[PileDrynessID]
inner join AQB_MON.[AQB_OB].[BurnYear] BUY on BUY.BurnYearID = BP.BurnYearID
inner join AQB_MON.[AQB_OB].[CurrentYear] CY on CY.CurrentYearID = BUY.CurrentYearID

Answer 3

这是一个使用CTE来很好地模拟内部变量构造的示例查询，如James Casey所述。您可以在您的SQL Server版本中测试它。

CREATE VIEW vwImportant_Users AS
WITH params AS (
    SELECT 
    varType='%Admin%', 
    varMinStatus=1)
SELECT status, name 
    FROM sys.sysusers, params
    WHERE status > varMinStatus OR name LIKE varType

SELECT * FROM vwImportant_Users

产出输出：

status  name
12      dbo
0       db_accessadmin
0       db_securityadmin
0       db_ddladmin

也可以通过JOIN

WITH params AS ( SELECT varType='%Admin%', varMinStatus=1)
SELECT status, name 
    FROM sys.sysusers INNER JOIN params ON 1=1
    WHERE status > varMinStatus OR name LIKE varType

也可以通过CROSS APPLY

WITH params AS ( SELECT varType='%Admin%', varMinStatus=1)
SELECT status, name 
    FROM sys.sysusers CROSS APPLY params
    WHERE status > varMinStatus OR name LIKE varType

Answer 4

或者使用 CTE（公共表表达式）作为子选择，例如：

from delta.tables import *

deltaTable = DeltaTable.forName(spark, "mytable")
df = deltaTable.history(1)
f.select(df["operationMetrics"]["numTargetRowsInserted"],
         df["operationMetrics"]["numTargetRowsUpdated"],
         df["operationMetrics"]["numTargetRowsDeleted"])

创建视图 - 声明变量

4 个答案: