将数据类型varchar转换为bigint时出错。在更新中

Question

我收到以下错误：

  

将数据类型varchar转换为bigint时出错。

执行以下查询时：

declare @MaxSizeMB BIGINT
set @MaxSizeMB = 50

DECLARE @Query varchar(8000)='' 

set @Query = 'UPDATE SPMC
              SET SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
              FROM PWI
              INNER JOIN SI ON SI.Id = PWI.SourceItemId
              INNER JOIN SPMC ON SPMC.SourceItemId = SI.Id
                              AND SI.ItemSize > ' + CAST(@MaxSizeMB AS bigint) + ' * 1024 * 1024 '  

print (@Query)   

Answer 1

您不计算查询中的@MaxSizeMB x 1024 x 1024，只是将结果连接到您的查询，如下所示：

declare @MaxSizeMB BIGINT
set @MaxSizeMB = 50*1024*1024

DECLARE @Query varchar(8000)='' 

set @Query=            
'Update SPMC
Set SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
FROM PWI
INNER JOIN SI on SI.Id = PWI.SourceItemId
INNER JOIN SPMC on SPMC.SourceItemId = SI.Id
AND SI.ItemSize > '+ cast(@MaxSizeMB as varchar(max)) 

print (@Query)   

您也可以在不使用动态SQL的情况下获得相同的结果。如下：

Update SPMC
Set SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
FROM PWI
INNER JOIN SI on SI.Id = PWI.SourceItemId
INNER JOIN SPMC on SPMC.SourceItemId = SI.Id
AND SI.ItemSize > (@MaxSizeMB *1024*1024)

Answer 2

由于MaxSizeMB已经BIGINT将其转换为BIGINT无效，您应该将计算出的值转换为varchar(max)。

declare @MaxSizeMB BIGINT
set @MaxSizeMB = 50

DECLARE @Query varchar(8000)='' 

set @Query=            
'Update SPMC
Set SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
FROM PWI
INNER JOIN SI on SI.Id = PWI.SourceItemId
INNER JOIN SPMC on SPMC.SourceItemId = SI.Id
AND SI.ItemSize > '+ cast(@MaxSizeMB * 1024 * 1024 as varchar(max))

print (@Query)  

Answer 3

试试这个：

 declare @MaxSizeMB BIGINT
set @MaxSizeMB = 50
DECLARE @Query varchar(8000)='' 

set @Query=            
'Update SPMC
Set SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
FROM PWI
INNER JOIN SI on SI.Id = PWI.SourceItemId
INNER JOIN SPMC on SPMC.SourceItemId = SI.Id
AND SI.ItemSize > '+ cast(cast(@MaxSizeMB as bigint) as varchar(max)) +' * 1024 * 1024 '  

print (@Query)

Answer 4

如果要生成动态查询，请将@MaxSizeMB强制转换为VARCHAR：

declare @MaxSizeMB BIGINT
set @MaxSizeMB = 50

DECLARE @Query VARCHAR(8000)='' 

set @Query=            
'Update SPMC
Set SPMC.HasBlockedSize = 1, SPMC.HasIssues = 1
FROM PWI
INNER JOIN SI on SI.Id = PWI.SourceItemId
INNER JOIN SPMC on SPMC.SourceItemId = SI.Id
AND SI.ItemSize > '+ cast(@MaxSizeMB as varchar) +' * 1024 * 1024 '  

print (@Query)