在期望条件的上下文中指定的非布尔类型的表达式

Question

我很厌倦看到这个错误:

消息102,级别15,状态1,过程sp_reorder_quantity,第16行
' - '附近的语法不正确.

它说明了这一点,因为它在第16行说明:

WHERE products.quantity_in_stock – products.reorder_level < @unit; 

它的意思products.quantity_in_stock是:An expression of non-boolean type specified in a context where a condition is expected.

CREATE PROCEDURE sp_reorder_quantity
(
    @unit       int
)
AS
   SELECT
      products.product_id,
      suppliers.name,
      suppliers.address,
      suppliers.city,
      suppliers.province,
      'qty' = products.quantity_in_stock,
      products.reorder_level
   FROM
      suppliers
   INNER JOIN
      products ON suppliers.supplier_id = products.supplier_id
   WHERE
      products.quantity_in_stock – products.reorder_level < @unit;
GO

Answer 1

这可能只是自动格式化搞砸了,但是–("en dash",U + 2013)与-("hyphen-minus",U + 002D)不是同一个字符.

尝试将其更改为:

WHERE products.quantity_in_stock - products.reorder_level < @unit;

如果我把它们放在彼此旁边,这更容易看出:

WHERE products.quantity_in_stock – products.reorder_level < @unit; -- yours
WHERE products.quantity_in_stock - products.reorder_level < @unit; -- fixed