postgresql 在 where 子句中使用“AND”时出现错误“参数必须是布尔类型”
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When using "AND" in where clause get error "argument must be type boolean"
提问by Celeritas
Error: argument of AND must be type boolean, not type character varying
错误：AND 的参数必须是布尔类型，而不是类型可变的字符
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
)
);
The part after the union is to include all partno from components that are not in productions (they should be counted as 0)
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）
采纳答案by davek
You have one bracket too many (after the attr IS NULL) and you have an aggregate function (the countin the second part) without a group by. Do you mean this:
您有一个括号太多（在 之后attr IS NULL）并且您有一个count没有group by. 你的意思是：
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;
