mysql - 查询不适用于在多个列上的 case 语句后添加 where 子句

Question

我有以下查询不适用于 WHERE 子句。我们将不胜感激。

UPDATE abc SET
col1 = CASE
WHEN a1_date < now() THEN "xyz"
END,
col2 = CASE
WHEN a2_date < now() THEN "xyz"
END,
col3 = CASE
WHEN a3_date < now() THEN "xyz"
END

WHERE a1_date != NULL AND a2_date != NULL

Answer 1

更改您的 WHERE 子句以使用 IS NOT NULL:

WHERE a1_date IS NOT NULL AND a2_date IS NOT NULL