简化 SQL where exists in 子句

Question

我想简化下面给定的过程，特别是我想删除大部分 where 子句过滤器，例如 IN 和 exists 子句。

为此，我使用了一个 CTE，还声明了一个临时 table 并用它来获取 select 查询，该查询自从它位于 where in 子句中以来就一直在说话。如果您能向我展示一些技巧以简化此查询，我将不胜感激。

ALTER PROCEDURE dbo.GetMappingBranchScenarios 
    @Mapping INT
    @UserId INT= NULL
    @BranchId INT = NULL

SELECT 
    BS.BranchId,
    NULLIF( CC.Code, '' ) AS Code,
    BS.BranchName,
    BS.Active      
FROM
    Branch BS 
LEFT OUTER JOIN 
    Code CC ON CC.BranchId = BS.BranchId    
LEFT OUTER JOIN 
    BranchRule BRE ON BRE.MappingId = @Mapping
                   AND BRE.BranchId = BS.BranchId  
WHERE
    (BS.Active = 1 
        OR EXISTS (SELECT * FROM BranchRule BRE 
                   WHERE BRE.BranchId = BS.BranchId 
                     AND BRE.BranchId > 0 
                     AND BRE.MappingId = @MappingId))  
     AND (@UserId IS NULL     
             OR BS.BranchId IN (SELECT BranchId 
                                FROM branch2mapping.dbo.ListBranch(@UserId))
             OR EXISTS (SELECT 1 FROM dbo.SecondaryMapping 
                        WHERE Id = @UserId AND Admin = 1))
    AND BS.BranchId = (CASE WHEN BranchId is NULL THEN BS.BranchID ELSE @BranchId END)
    AND CC.Code =  (CASE WHEN @Code IS NULL THEN CC.Code ELSE @Code END)
ORDER BY
    CC.Code ASC

到目前为止我做了什么：

IF OBJECT_ID('tempdb..#Temp', 'U') IS NOT NULL
    DROP TABLE #Temp

CREATE TABLE #Temp (BranchId INT) 

SELECT BranchId 
FROM branch2mapping.dbo.ListBranch(@UserId)

;WITH CTE AS 
(
    SELECT 
        BS.BranchId,
        NULLIF(CC.Code, '' ) AS Code,
        BS.BranchName, BS.Active      
    FROM
        Branch BS 
    LEFT OUTER JOIN 
        Code CC ON CC.BranchId = BS.BranchId    
    LEFT OUTER JOIN 
        BranchRule BRE ON BRE.MappingId = @Mapping
                       AND BRE.BranchId = BS.BranchId  
)
SELECT *  
FROM CTE
WHERE 
    (CTE.Active = 1     
     OR EXISTS (SELECT * FROM BranchRule BRE 
                WHERE BRE.BranchId = CTE.BranchId 
                  AND BRE.BranchId > 0 
                  AND BRE.MappingId = @MappingId))  
     AND (@UserId IS NULL     
             OR BS.BranchId IN (SELECT * FROM #Temp)
             OR EXISTS (SELECT 1 FROM dbo.SecondaryMapping 
                        WHERE Id = @UserId AND Admin = 1) 
         )
     AND BS.BranchId = (CASE WHEN BranchId is NULL THEN CTE.BranchID ELSE @BranchId END)
     AND CTE.Code = (CASE WHEN @Code IS NULL THEN CTE.Code ELSE @Code END)
 ORDER BY
     CTE.Code ASC

感谢您的帮助。

Answer 1

你能不能试一试，如果这更快，并且仍然使用不同的过滤条件返回相同的值？

ALTER PROCEDURE dbo.GetMappingBranchScenarios 
    @Mapping INT
    @UserId INT= NULL
    @BranchId INT = NULL


DECLARE @IsRuleExists BIT;
DECLARE @IsUrerADmin BIT;

IF EXISTS
(
    SELECT 1
    FROM Branch BS
    INNER JOIN BranchRule BRE 
        ON BRE.BranchId = BS.BranchId 
        AND BRE.BranchId > 0 
        AND BRE.MappingId = @MappingId
) 
BEGIN;
    SET @IsRuleExists = 1;
END;

IF EXISTS 
(
    SELECT 1 
    FROM dbo.SecondaryMapping 
    WHERE Id = @UserId AND Admin = 1
) OR @UserId IS NULL  
BEGIN;
    SET @IsUrerADmin = 1;
END;

CREATE TABLE #Branches
(
    [BranchId] INT
);

INSERT INTO #Branches ([BranchId])
SELECT BranchId 
FROM branch2mapping.dbo.ListBranch(@UserId);


SELECT 
    BS.BranchId,
    NULLIF( CC.Code, '' ) AS Code,
    BS.BranchName,
    BS.Active      
FROM Branch BS 
LEFT OUTER JOIN Code CC 
    ON CC.BranchId = BS.BranchId     
WHERE 
(
    BS.Active = 1 OR @IsRuleExists = 1
)  
AND 
(
    @IsUrerADmin = 1   
    OR 
    BS.BranchId IN (SELECT BranchId FROM #Branches)
)
AND BS.BranchId = (CASE WHEN BranchId is NULL THEN BS.BranchID ELSE @BranchId END)
AND CC.Code =  (CASE WHEN @Code IS NULL THEN CC.Code ELSE @Code END)
ORDER BY CC.Code ASC;

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