给 EXEC (@Variable) 一个列名和串联

Question

我正在尝试编写一个存储过程，该过程将在我们的客户尝试升级之前检查孤立数据，因为孤立记录可能会导致问题。这是我迄今为止所拥有的；

IF EXISTS (SELECT * FROM sys.objects WHERE type = 'P' AND name = 'DetectOrphanDataBeforeUpgrade')
DROP PROCEDURE [dbo].[DetectOrphanDataBeforeUpgrade]
GO

CREATE PROCEDURE [dbo].[DetectOrphanDataBeforeUpgrade]

@TenantId   INT = NULL

AS
BEGIN

DECLARE @OrphanAuditItems NVARCHAR(MAX)
DECLARE @OrphanAuditAnswers NVARCHAR(MAX) 
DECLARE @OrphanAuditQuestion NVARCHAR(MAX)

------------------------------------------------------------------------------------------------
/* Throw an error if the TenantId is NULL or Invalid.               */
------------------------------------------------------------------------------------------------
IF @TenantId IS NULL OR @TenantId NOT IN (SELECT Tenants FROM [Application].[dbo].[TenantIdNumber])

BEGIN
    THROW 51000, '@TenantId is invalid because it is NULL or does not exist.', 1;
END


------------------------------------------------------------------------------------------------
/* Checks for Orphan records related to the Audits table                */
------------------------------------------------------------------------------------------------
SET @OrphanAuditItems = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems] 
                                                    WHERE FK_Audit NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

SET @OrphanAuditAnswers = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditAnswers] 
                                                        WHERE AuditItemId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems])'

SET @OrphanAuditQuestion = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditQuestion] 
                                                        WHERE AuditId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

EXEC (@OrphanAuditItems)
EXEC(@OrphanAuditAnswers)
EXEC(@OrphanAuditQuestion)

END;

目前，这个脚本正在运行，但是输出是；

我想在一行中返回结果，并且每列都有自己的名称，例如：@OrphanAuditItems 结果显示为列名：OrphanAuditItems，等等。

实现这一目标的最佳方法是什么？

谢谢，汤姆

Answer 1

您需要将 3 个动态 SQL 混合到 1 个中，返回 3 列，或者保留每个动态 SQL 但在最后混合它们的结果。有以下两种可能的解决方案：

一种解决方案是使用UNION ALL和PIVOT来获取 1 行 3 列，所有这些都在动态 SQL 中。

更改这部分：

DECLARE @OrphanAuditItems NVARCHAR(MAX)
DECLARE @OrphanAuditAnswers NVARCHAR(MAX) 
DECLARE @OrphanAuditQuestion NVARCHAR(MAX)

--.....

SET @OrphanAuditItems = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems] 
                                                    WHERE FK_Audit NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

SET @OrphanAuditAnswers = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditAnswers] 
                                                        WHERE AuditItemId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems])'

SET @OrphanAuditQuestion = N'SELECT COUNT(*) FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditQuestion] 
                                                        WHERE AuditId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

EXEC (@OrphanAuditItems)
EXEC(@OrphanAuditAnswers)
EXEC(@OrphanAuditQuestion)

为了这：

DECLARE @DynamicSQL NVARCHAR(MAX) = N'
    ;WITH PrePivot AS
    (
        SELECT 
            Amount = COUNT(*),
            Type = ''OrphanAuditItems''
        FROM 
            [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems] 
        WHERE 
            FK_Audit NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits]) 

        UNION ALL

        SELECT 
            Amount = COUNT(*),
            Type = ''OrphanAuditAnswers''
        FROM 
            [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditAnswers] 
        WHERE 
            AuditItemId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems])

        UNION ALL

        SELECT 
            Amount = COUNT(*),
            Type = ''OrphanAuditQuestion''
        FROM 
            [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditQuestion] 
        WHERE 
            AuditId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits]) 
    )
    SELECT
        P.OrphanAuditItems,
        P.OrphanAuditAnswers,
        P.OrphanAuditQuestion
    FROM
        PrePivot AS T
        PIVOT (
            MAX(T.Amount) FOR T.Type IN ([OrphanAuditItems], [OrphanAuditAnswers], [OrphanAuditQuestion])
        ) AS P '

-- PRINT (@DynamicSQL)
EXEC (@DynamicSQL)

确保PRINT在执行之前使用 来验证生成的 SQL EXEC。

sp_executesql另一个解决方案是使用参数将值检索到变量中OUTPUT：

-- Items
DECLARE @OrphanAuditItems INT

DECLARE @DynamicSQL NVARCHAR(MAX) = N'
    SELECT
        @OrphanAuditItems = COUNT(*)
    FROM
        #OrphanResults AS O
        CROSS JOIN [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems]
    WHERE 
        FK_Audit NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

EXEC sp_executesql 
    @stmt = @DynamicSQL,
    @params = N'@OrphanAuditItems INT OUTPUT',
    @OrphanAuditItems = @OrphanAuditItems OUTPUT


-- Answers
DECLARE @OrphanAuditAnswers INT

SET @DynamicSQL = N'
    SELECT 
        @OrphanAuditAnswers = COUNT(*) 
    FROM 
        [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditAnswers] 
    WHERE 
        AuditItemId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditItems])'

EXEC sp_executesql 
    @stmt = @DynamicSQL,
    @params = N'@OrphanAuditAnswers INT OUTPUT',
    @OrphanAuditAnswers = @OrphanAuditAnswers OUTPUT


-- Questions
DECLARE @OrphanAuditQuestion INT

SET @DynamicSQL = N'
    SELECT 
        @OrphanAuditQuestion = COUNT(*) 
    FROM 
        [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[AuditQuestion] 
    WHERE 
        AuditId NOT IN (SELECT SystemID FROM [Dynamic].['+ CAST (@TenantId AS NVARCHAR) +'].[Audits])'

EXEC sp_executesql 
    @stmt = @DynamicSQL,
    @params = N'@OrphanAuditQuestion INT OUTPUT',
    @OrphanAuditQuestion = @OrphanAuditQuestion OUTPUT

SELECT
    OrphanAuditItems = @OrphanAuditItems,
    OrphanAuditAnswers = @OrphanAuditAnswers,
    OrphanAuditQuestion = @OrphanAuditQuestion

我发现后者比第一个更加灵活和可读。