在一个 SQL 查询中涉及不同列的两个单独更新

Question

UPDATE users SET col1 = '' WHERE user_id IN (a, b)
UPDATE users SET col2 = '' WHERE user_id IN (c, d)

Is it possible to write a single update query that can provide the same result?

Answer 1

You can use a case expression:

UPDATE users
    SET col1 = (CASE WHEN user_id IN (a, b) THEN '' ELSE col1 END),
        col2 = (CASE WHEN user_id in (c, d) THEN '' ELSE col2 END)
    WHERE user_id in (a, b, c, d);