在 where 子句中使用“AND”时出现错误“参数必须是布尔类型”

Question

错误：AND 的参数必须是布尔类型，而不是不同类型的字符

SELECT 
    partno, 
    count(manufacturer) 
FROM 
    components 
WHERE 
    partno IN (SELECT partno FROM productions 
               WHERE 
                    year = 2005
                AND attr is NULL
              ) 
GROUP BY partno
UNION
SELECT 
    partno, 
    count(manufacturer) 
FROM components 
WHERE 
    partno IN (SELECT partno FROM productions 
               WHERE 
                   year = 2005
               AND attr is NULL
              ) 
GROUP BY partno
) 
AND (
        partno NOT IN (SELECT partno FROM components
    )
); 

union 后面的部分是包括所有不在生产中的组件的partno（它们应该算作0）

Answer 1

你有一个括号太多（在 后面attr IS NULL）并且你有一个没有 的聚合函数（count第二部分中的）group by。你的意思是这样吗：

select partno, count(manufacturer) 
from components 
where partno in 
(
   select partno from productions where year=2005 and attr is NULL
) 
group by partno

UNION

select partno, count(manufacturer) 
from components 
where partno in 
(
    select partno from productions where year=2005 and attr is NULL
) 
AND partno not in (select partno from components)
group by partno;