Question

我使用此代码试图获得4,202和＆amp;的总和。 203但是它还给我错误

SELECT *
FROM
( SELECT id,fieldNumber,fieldData FROM iso_fields) AS SourceTable
PIVOT
(
 SUM(fieldData) 
FOR fieldNumber IN ([4],[202],[203])
) AS PivotTable;

错误：

Operand data type varchar is invalid for sum operator.

原因：

Table using varchar instead of int

我该怎么办？没有办法改变桌面。

Answer 1

fieldData的数据类型为varchar，因此错误。如果fieldData列没有任何varchar数据，那么您可以在INT源查询中进行显式转换为pivot。

SELECT *
FROM
( SELECT id,fieldNumber, fieldData FROM iso_fields) AS SourceTable
PIVOT
(
 MAX(fieldData) 
FOR fieldNumber IN ([4],[202],[203])
) AS PivotTable;

Answer 2

如果您确保所有fieldData值都是数字，则可以使用cast或convert：

SELECT *
FROM
( SELECT id,fieldNumber,fieldData FROM iso_fields) AS SourceTable
PIVOT
(
SUM(cast(fieldData as int)) 
FOR fieldNumber IN ([4],[202],[203])
) AS PivotTable;

但是如果不确保fieldData中的数值，可以使用try_cast或try_convert（SQL Server 2012及更高版本）：

SELECT *
FROM
( SELECT id,fieldNumber,fieldData FROM iso_fields) AS SourceTable
PIVOT
(
SUM(try_cast(fieldData as int))
FOR fieldNumber IN ([4],[202],[203])
) AS PivotTable;

SQL：Varchar对Sum运算符无效

2 个答案: