将您的where子句更改为：

Change your where clause to:

WHERE AGT_INV_DATE
BETWEEN
DATEADD(day, DATEDIFF(day,0,GETDATE())-1,0)
AND
DATEADD(day, DATEDIFF(day,0,GETDATE()),0)

SELECT COUNT(*) as 'count'
FROM dbo.INVENTORY
WHERE INV_NO IS NULL AND AGT_INV_DATE BETWEEN DATEADD(dd, -1,GETDATE()) AND GETDATE()

详情请见：日期和时间数据类型和函数（Transact-SQL） [ ^ ]

SELECT * FROM INVENTORY WHERE INV_DATE BETETEET GETDATE（） - 1和GETDATE（）