COUNT() 对 except 的结果

Question

我有一个这样的查询：

SELECT
    id
FROM
    table1
INNER JOIN
    ...
WHERE
    ...
    AND eventtype IN (2000120, 2000121, 2000122, 2000123, 2000130)

EXCEPT

SELECT
    id
FROM
    table1
INNER JOIN
    ...
WHERE
    ...
    AND eventtype IN (2000123,2000130,2000134,2000135)

请注意，除了最后一个 where 子句之外，这两个查询都是相同的。

我现在想计算上述查询返回的记录数。

如何？

非常感谢

Answer 1

使用COUNT并将其包裹在一个SUBQUERY

SELECT COUNT(ID)
FROM (
        SELECT id
        FROM table1
        INNER JOIN...
        WHERE...
                AND eventtype IN ( 2000120, 2000121, 2000122, 2000123, 2000130 )
        EXCEPT
        SELECT id
        FROM table1
        INNER JOIN...
        WHERE...
                AND eventtype IN ( 2000123, 2000130, 2000134, 2000135 )
        ) s